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University of 
St. Michael s College, Toronto 





W. D. ROSS, M.A., HON. LL.D. (EDIN.) 




















Special thanks are due to the Trustees of the 

Jowett Copyright Fund for their assistance 

towards the publication of this Volume 


IN this volume the last part of the translation to be published 
takes its place immediately before the first part to be 
published, the Parva Naturalia, which appeared in 1908. 
I must ask the indulgence of readers for the long interval 
that has elapsed between the two. The Great War, the 
death of some of the contributors before their translations 
were completed, the necessity for a considerable interchange 
of views between translators and editor, these have been 
among the causes of delay. I hope that by delay something 
has been gained as well as something lost ; I am conscious 
of realizing much more fully now than I did in 1908 the 
nature of the problem of translating Aristotle, and I hope 
that the later contributors have learned something from the 
work of their predecessors. 

In the series as a whole, indexes have been placed some 
times after single works, sometimes after groups of works. 
It may help readers in the use of these if they are told exactly 
where to look for them. Indexes will be found as follows : 

In vols. IV, VI, VII, VIII at the end. 

In vol. I after Analytica Posterior a ; after De Sophisticis 

In vol. II after Physica\ after Zte Caelo\ after De Genera- 
tione et Corntptione. 

In vol. Ill after Metcorologica; after De Anima; after 
Parva Naturalia ; after De Mundo ; after De Spiritu. 

In vol. V after De Partibus Animalium ; after De Incessu 
Animalium \ after De Generations Animalium. 

In vol. IX after Ethica Nicomachea ; after Magna 
M or alia ; after De Virtutibus et Vitiis. 

In vol. X after Politica ; after Oeconomica ; after Athenien- 
sium Respnblica. 

In vol. XI after Rhetorica\ ztterR/ietorica acl Alexandrum ; 
after Poetica. 

I have to thank Mr. George Brown, Lecturer in Logic in 
the University of Glasgow, for kindly reading the proof- 
sheets of the De Anima, as he did those of the Physics. And 


in taking leave of this work of many years I must thank 
the Master and Fellows of Balliol, the Trustees of the Jowett 
Copyright Fund, and the Delegates of the Press for their 
financial support of the translation ; my former co-editor, 
Prof. J. A. Smith, for the large part he played in the early 
stages of the work and for the advice which has always been 
at my disposal since ; and the officials and staff of the Press 
for their interest and care in the production of the work. 

21 February, 1931. 


IT was the desire of the late Master of Balliol, Dr. Benjamin 
Jovvett, as formulated in his will, that the proceeds from the 
sale of his works, the copyright in which he bequeathed to 
Balliol College, should be used to promote the study of 
Greek Literature, especially by the publication of new 
translations and editions of Greek authors. In a codicil to 
his will he expressed the hope that the translation of 
Aristotle s works begun by his own translation of the Politics 
should be proceeded with as speedily as possible. The 
College resolved that the funds thus accruing to them should, 
in memory of his services to the College and to Greek letters, 
be applied to the subvention of a series of translations of the 
works of Aristotle. Through the co-operation, financial and 
other, of the Delegates of the University Press it has now 
become possible to begin the realization of this design. By 
agreement between the College and Delegates of the Press 
the present editors were appointed to superintend the 
carrying out of the scheme. The series, of which the first 
instalment is now brought before the public, is published at 
the joint expense and risk of the College and the Delegates 
of the Press. 

The editors have secured the co-operation of various 
scholars in the task of translation. The translations make 
no claim to finality, but aim at being such as a scholar 
might construct in preparation for a critical edition and 
commentary. The translation will not presuppose any 
critical reconstitution of the text. Wherever new readings 
are proposed the fact will be indicated, but notes justificatory 
of conjectural emendations or defensive of novel interpreta 
tions will, where admitted, be reduced to the smallest 
compass. The editors, while retaining a general right of 
revision and annotation, will leave the responsibility for 

1 The Parva Naturalia (1908) was the first part of the series to be 


each translation to its author, whose name will in all cases 
be given. 

Translators have been found for the Organon, Physics, 
De Caelo, De Anima, His tor ia Animalium, De Animalium 
Generatione, De Insecabiltbus Lineis, Metaphysics, Eudemian 
Ethics, Rhetoric, and Poetics, and it is hoped that the series 
may in course of time include translations of all the extant 
works of Aristotle. The editors would be glad to hear of 
scholars who are willing to undertake the translation of such 
treatises as have not already been provided for, and invite 
communications to this end. 

The editors desire to acknowledge their obligation to 
Mr. Charles Cannan for valuable aid in the revision of the 
present volume, and to Mr. G. R. T. Ross for the preparation 
of the Index. 

J. A. S. 
W. D. R. 

December, 1907. 






Oxford University Press 

London Edinburgh Glasgow Copenhagen 

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Bombay Calcutta Madras Shanghai 
Humphrey Milford Publisher to the UNIVERSITY 

Printed in England 


THE translation of the Meteorologica which follows is 
the work of a scholar whose death was one of the severest 
losses which the University of Oxford suffered through 
the Great War. Erwin Wentworth Webster came up to 
Wadham as a Scholar in 1898. Besides taking First Classes 
of unusual brilliance in Classical Moderations and in Literae 
Humaniores, he won the Taylorian Scholarship for German 
and the John Locke Scholarship for Mental Philosophy. 
Shortly after taking his degree he was elected to a Fellow 
ship of his own College, and undertook tutorial work in 
philosophy, to which he devoted himself with immense 
energy and great success. He was (in addition to his 
general philosophical interests) a keen student of Aristotle, 
and one of the most faithful members of the Aristotelian 
Society which met week after week under the presidency 
first of Professor Bywater and then of Professor J. A. Smith, 
and at which many of us younger men learned from these 
masters of the art how to tackle the interpretation of the 
Greek philosophers. He took up the Meteorologica fairly 
early as a special study. His notes, apart from the trans 
lation, are unfortunately not in a suitable form for publica 
tion, but show how wide and how deep was his study of all 
that bore on the subject, and how valuable a contribution 
he would have made, if he had been spared, to our know 
ledge of it. But things were otherwise ordained. On the 
outbreak of war he offered himself for service in the Royal 
Flying Corps. An accident during his training compelled 
him to give up this prospect ; and he thereupon applied for 
and received a commission in the I3th King s Royal Rifle 
Corps, in which he later became a Captain. He went to 

646-21 A 2 


France in July, 1915, and saw much hard service there. 
He was more than once practically ordered home to 
hospital, but insisted on remaining with his battalion. He 
was killed at Monchy-le-Preux, near Arras, on the ninth of 
April, 1917, while leading his company in an attack. 

All who knew Webster will remember the modesty 
which was one of the leading features of a most attractive 
personality. Even if he had lived to give the finishing 
touches to his translation, he would have been the first to 
depreciate its merits, and I cannot hope that, lacking as it 
does his final correction, it will be found free from error. 
But I think that the errors will not be found to be very 
serious ones/and it is a satisfaction, though a melancholy 
one, to give to the world this slight memorial of one who 
if he had lived would undoubtedly have made a considerable 
mark both as a teacher and as a student. 

The translation has been based on Bekker s quarto text, 
but in editing it I have made constant use of the valuable 
new edition of the Meteor ologica by my former pupil 
Mr. F. H. Fobes, which gives with admirable completeness 
and precision the whole evidence for the text, and in very 
many respects improves on all previous editions. 




1. Summary of subject-matter of meteorology. 

2. The material and the efficient cause of the phenomena to be 


3. The position of air and fire relatively to the celestial sphere. Why 

clouds and water do not form in ether. 

4. The cause of shooting-stars and the like. 

5. The cause of the appearance of * chasms , c., in the sky. 

6. Refutation of earlier theories of comets. 

7. The cause of comets. 

8. The milky way. 

9. The causes of rain, and the difference between cloud and mist. 

10. The causes of dew and hoar-frost. 

11. The causes and concomitants of snow. 

12. Hail where and when it is produced. 

13. Winds, rivers, and springs. 

14. Why the same parts of the earth are not always watered by 

rivers, or always dry. Floods. 


1. Three theories of the origin of the sea. It cannot have springs. 

Why it flows as it does. 

2. Its place. It is the end rather than the beginning of water. Why 

it is not increased by the influx of rivers. 

3. Why is it salt? Is it eternal? The cause of different tastes and 

colours in water. 

4. The causes of winds. 

5. Why winds blow at some times and not at others. From where, 

and when, each wind blows. 

6. The direction of the winds ; which are contrary ; and which can 

blow together. Their number, concomitants, and natures. 

7. Three theories of earthquakes. 

8. The causes of earthquakes. Indications that they are due to 


9. Early theories of thunder and lightning. 




1. The causes of, and difference between, ecnephias, typhon, and 

prester. The kinds of thunderbolt. 

2. The causes and concomitants of halos. 

3. Why halos are circular, and what they indicate. 

4. The rainbow how it is produced by reflection, and the causes of 

its properties (e.g. its colours). How it differs from the halo. 

5. Some properties of the rainbow. 

6. The causes of rods and mock suns. 


1. Hot and cold are active, dry and moist passive principles. True 

or natural generation is due to these. The contrary of true 
generation is putrefaction. Putrefaction further considered. 

2. Concoction and inconcoction. 

3. Three kinds of concoction ripening, boiling, broiling; and their 


4. Dry and moist, and the properties consequent on them in com 

posite bodies hard and soft. 

5. Every well-defined body must be hard or soft, and solid. Solidifica 

tion and its causes. 

6. Things that can be solidified are made either of water, or of earth 

and water. Various modes of solidification and solution. 

7. Things are thickened by fire or by cold according as they have 

more water or earth in them. 

8 The properties of composite bodies nineteen positive and nine 
teen negative. What can and what cannot be solidified ; what 
can and what cannot be melted. 

9. The remaining seventeen properties. 

10. Homoeomerous bodies. 

11. Which mixtures are warm and which are cold. 

12. Homoeomerous bodies are [composed of the elements. End and 

function more evident in non-homoeomerous bodies than in the 
homoeomerous bodies which compose them, and in these than 
in the elements. 



I WE have already discussed the first causes of nature, 20 
and all natural l motion, 2 also the stars ordered in the 
motion of the heavens, 3 and the physical elements 
enumerating and specifying them and showing how they 
change into one another and becoming and perishing in 
general. 4 There remains for consideration a part of this 
inquiry which all our predecessors called meteorology. 
It is concerned with events that are natural, though their 338 
order is less perfect than that of the first of the elements 21 
of bodies. They take place in the region nearest to the 
motion of the stars. 5 Such are the milky way, and comets, 
and the movements of meteors. 6 It studies also all the affec 
tions we may call common to air and water, 7 and the kinds 
and parts of the earth and the affections of its parts. 8 These 
throw light on the causes of winds and earthquakes and all 339 
the consequences the motions of these kinds and parts involve. 
Of these things some puzzle us, while others admit of explana 
tion in some degree. Further, the inquiry is concerned with 
the falling of thunderbolts and with whirl winds and fire-winds, 
and further, the recurrent affections produced in these same 5 
bodies by concretion 10 . When the inquiry into these matters 
is concluded let us consider n what account we can give, in 
accordance with the method we have followed, of animals 
and plants, both generally and in detail. When that has 
been done we may say that the whole of our original 
undertaking will have been carried out. 

i.e. neither purposive nor constrained. 
Physics. 3 De Caelo, esp. i and ii. 

De Gen. et Corr., and perhaps De Cae/o, iii, iv. 
i. e. just below the sphere of the moon. 
Bk. i. 4-8. 7 Bks. i. 9-12, iii. 2-6. 378" 14. 

Bks. i. 13-ii. 3. Bk. ii. 4-8. 10 Bks. ii. 9, iii. I. 

11 De An., Parv. Nat., H.A., P. A., J.A., G.A. 


10 After this introduction let us begin by discussing our 
immediate subject. 

We have already laid down that there is one physical 2 
element which makes up l the system of the bodies that move 
in a circle, and besides this four bodies owing their existence 
to the four principles, 2 the motion of these latter bodies being 

15 of two kinds : either from the centre or to the centre. 
These four bodies are fire, air, water, earth. Fire occupies 
the highest place among them all, earth the lowest, and two 
elements correspond to these in their relation to one 
another, air being nearest to fire, water to earth. The" 

20 whole world surrounding the earth, 4 then, the affections of 
which are our subject, is made up of these bodies. This 
world necessarily has a certain continuity with the upper 
motions : consequently all its power and order is derived 
from them. (For the originating principle of all motion is 

25 the first cause. Besides, that element is eternal and its 
motion has no limit in space, but is always complete ; 
whereas all these other bodies have separate regions which 
limit one another.) 5 So we must treat fire and earth and 
the elements like them as the material causes of the events 

30 in this world 4 (meaning by material what is subject and is 
affected), but must assign causality in the sense of the 
originating principle of motion to the influence of the 
eternally moving bodies. 

Let us first recall G our original principles and the 3 

1 Read e fa in 1. 12 with Vicomercato. 

2 Hot, cold, dry, moist. 

3 Read commas for colons in 11. 15, 17, 18, and a colon for the full 
stop in 1. 19, where the apodosis begins. 

4 The sublunary world. 

5 30ev . . . aXX^Xcoi/ (11. 23-27) is parenthetical. 

c The argument of this confused chapter seems to be as follows : 
339 a 33- b 2 introductory; 339 b 2-i6 the main question is stated to be 
the nature of air and its relations to the other elements : 339 b 16- 
340 a 1 8 a preliminary question about the nature of the element in the 
celestial sphere is discussed. Two views are dismissed, (a) that the 
stars and the interval between them are of fire, while the space from 
the earth to the moon is air, 339 b 30-340* 3, (b) that the whole world 
from the earth to the stars, including the intervals between them, is of 
air, 340*3-18. 340*19-24 the original question is restated; it now 
appears in two parts, (a) relation of fire and air to the celestial element, 

BOOK I. 3 339 a 

distinctions already drawn and then explain the milky 
way and comets and the other phenomena akin to these. 35 

Fire, 1 air, water, earth, we assert, originate from one 
another, and each of them exists potentially in each, as all 339 b 
things do that can be resolved into a common and ultimate 
substrate. 2 

The first difficulty is raised by what is called the air. 
What are we to take its nature to be in the world sur 
rounding the earth ? And what is its position relatively to 5 
the other physical elements. (For there is no question as 
to the relation of the bulk of the earth to the size of the 
bodies which exist around it, since astronomical demonstra 
tions have by this time proved to us that it is actually far 
smaller than some individual stars. As for the water, it is 
not observed to exist collectively and separately, nor can 10 
it do so apart from that volume of it which has its seat about 
the earth : the sea, that is, and rivers, which we can sec, 
and any subterranean water that may be hidden from our 
observation.) The question is really about that which lies 
between the earth and the nearest stars. Are we to 
consider it to be one kind of body or more than one? 15 
And if more than one, how many are there and what are 
the bounds of their regions ? 

We have already described and characterized the first 
element, and explained that the whole world of the upper 
motions is full of that body. 15 

This is an opinion we are not alone in holding : it 20 
appears to be an old assumption and one which men have 
held in the past, for the word ether has long been used to 
denote that element. Anaxagoras, 4 it is true, seems to me 
to think that the word means the same as fire. For 

(b) question about the origination of heat by the celestial bodies (now 
recognized as not themselves hot) on earth. This change in the formu 
lation of the question is clue to the answers given to the preliminary 
question. 34o :i 24~ b 3 a preliminary discussion about the nature of air 
and difficulties raised about the formation of clouds in it: 34o b 4~ 
341 a 12 question (a) is answered and the difficulty about clouds solved : 
341 a 12-end question (b} solved. 

1 Read &} with JFHN and Thurot in 1. 36. 

2 Cp. De Gen. et Corr. ii. 4, DC Caelo, iii. 6 and 7. 

3 De Cach, i. 3. 

4 Ibid. i. 2o b 2. 


he thought that the upper regions were full of fire, and that 
men l referred to those regions when they spoke of 
25 ether. In the latter point he was right, for men seem to 
have assumed that a body that was eternally in motion 2 
was also divine 3 in nature ; and, as such a body was different 
from any of the terrestrial elements, they determined to 
call it ether . 

For the same opinions appear in cycles among men not 
once nor twice, but infinitely often. 

-o Now there are some who maintain that not only the 
bodies in motion but that which contains them is pure fire, 
and the interval between the earth and the stars air : but 
if they had considered what is now satisfactorily established 
by mathematics, they might have given up this puerile 
opinion. For it is altogether childish to suppose that the 
35 moving bodies are all of them of a small size, because they 
seem so to us, looking at them from the earth. 

This is a matter which we have already discussed in our 
treatment of the upper region, 4 but we may return to the 
point now. 

34O a If the intervals were full of fire and the bodies consisted 
of fire every one of the other elements would long ago have 

However, they cannot simply be said to be full of air 
either ; for even if there were two elements to fill the space 
between the earth and the heavens, 5 the air would far exceed 
the quantity required to maintain its proper proportion to 
5 the other elements. For the bulk of the earth (which 
includes the whole volume of water) is infinitesimal in 
comparison with the whole world that surrounds it. Now 
we find that the excess in volume is not proportionately 
10 great where water dissolves into air or air into fire. 
Whereas the proportion between any given small quantity 
of water and the air that is generated from it ought to hold 
good between the total amount of air and the total amount of 
water. Nor does it make any difference if any one denies 7 

1 Read KaKfivovs (Thurot) in 1. 24. 2 6tov. 

4 De Caelo, ii. 298* 15 (the smallness of the earth). 

5 The outermost heaven. 8 Kmpedocles. 
7 Read ^a\ with EJF in 1. 13. 

BOOK I. 3 340 

that the elements originate from one another, but asserts 
that they are equal in power. For on this view it is 15 
certain amounts of each that are equal in power, just as 
would be the case if they actually originated from one 

So it is clear that neither air nor fire alone 2 fills the 
intermediate space. 3 

It remains to explain, after a preliminary discussion of 
difficulties, the relation of the two elements air and fire to 
the position of the first element, and the reason why the 20 
stars in the upper region impart heat 4 to the earth and its 
neighbourhood. Let us first treat of the air, as we pro 
posed, 5 and then go on to these questions. 

Since c water is generated from air, and air from water, 
why are clouds not formed in the upper air ? They ought 25 
to form there the more, the further from the earth and the 
colder that region is. For it is neither appreciably near to 
the heat of the stars, nor to the rays reflected from the 
earth. It is these that dissolve any formation by their 30 
heat and so prevent clouds from forming near the earth. 7 
For clouds gather at the point where the reflected rays 

1 De Gen. et Corr. ii. 6. A. there argues that if the elements are 
comparable a common substrate and transmutation are implied. But 
Empedocles says the elements are equal while denying their trans 
mutation. If he means (a) equal in quantity , there is something 
common to them in virtue of which they are measured, and transmuta 
tion follows. If he means (b) equal in power , e. g. I c.c. water has as 
much refrigerating power as 10 c.c. air, the water and the air must 
have something in common in virtue of which they refrigerate, and 
transmutation follows again. A. might prove on the same principle 
that since gold and lead can both be weighed they must be trans- 

2 Nor both together. 

3 Between the earth and the outermost heaven. The conclusion, 
which is not expressed, is : therefore there must be a fifth element in 
the celestial region. 

4 As soon as the stars and the upper region are not considered to be 
of fire, this requires explanation. 

5 This is misleading if it refers back to 339 b 3, since it is not so much 
the aporetic discussion about the clouds in the air 34o a 24~ b 3, as the 
two discussions in 34Q b 4-34i a 36, especially the first 34o b 3~34i a 12, 
which answer the original question. 

6 This passage 340* 24- b 3 is purely aporetic. No account is taken 
of results already arrived at. 

7 For A. s conception of the stratification of the air, cp. (Albert, 
Meteor. Theorien d. gr. Altertums, 476 sqq. (doubtful on some details), 
Meteor. 34O b 29, 361* 22, 373*23 and note. 


disperse in the infinity of space and are lost. To explain 
this we must suppose either that it is not all air from which 
water is generated, or, if it is produced from all air alike, 
that what immediately surrounds the earth is not mere air, 
but a sort of vapour, and that its vaporous nature is the 

35 reason why it condenses back to water again. But if the 
whole of that vast region is vapour, the amount of air and of 
water will be disproportionately great. For the spaces left by 
34 the heavenly bodies must be filled by some element. This 
cannot be fire, for then all the rest would have been dried 
up. Consequently, what fills it must be air and the water that 
surrounds the whole earth vapour being water dissolved. 

After this exposition of the difficulties involved, let us 

5 go on to lay down the truth, with a view at once to what 

follows and to what has already been said. The upper 

region as far as the moon T we affirm to consist of a body 

distinct both from fire and from air, but varying in degree 

10 of purity and in kind, especially towards its limit on the 
side of the air, and of the world surrounding 2 the earth. 
Now the circular motion of the first element and of the bodies 
it contains dissolves, and inflames by its motion, whatever 
part of the lower world is nearest to it, and so generates 
heat. From another point of view we may look at the 

15 motion as follows. The body that lies below the circular 
motion of the heavens is, in a sort, matter, and is potentially 
hot, cold, dry, moist, and possessed of whatever other quali 
ties are derived from these/ But it actually acquires or 
retains one of these in virtue of motion or rest, the cause 
and principle of which has already been explained. 4 So at 

20 the centre and round it we get earth and water, the heaviest 
and coldest elements, by themselves ; round them and 
contiguous 5 with them, air and what we commonly call 
fire. It is not really fire, for fire is an excess of heat and 
a sort of ebullition ; 6 but in reality, of what we call air, 

25 the part surrounding the earth is moist and warm, because 
it contains both vapour and a dry exhalation from the 

1 i.e. the region between the air properly so called and the moon. 

2 i.e. immediately surrounding. 

3 De Gen. et Corr. ii. 2. 4 Ibid. ii. 10. 
5 Omitting T in 1. 21, with JFA1. 6 Cp. 341 21. 

BOOK I. 3 340 

earth. But the next part, above that, is warm and dry. 
For vapour is naturally moist and cold, 1 but the exhalation 
warm and dry ; and vapour is potentially like water, the 
exhalation potentially like fire. So we must take the 
reason why clouds are not formed in the upper region to 3 
be this : that it is filled not with mere air but rather with 
a sort of fire. 

However, it may well be that the formation of clouds in 
that upper region is also prevented by the circular motion. 
For the air round the earth is necessarily all of it in motion, 
except that which is cut off inside the circumference which 35 
makes the earth a complete sphere. 2 In the case of winds 
it is actually observable that they originate in marshy 
districts of the earth ; and they do not seem to blow above 
the level of the highest mountains. It is the revolution of 
the heaven which carries the air with it and causes its 
circular motion, fire being continuous with the upper 
element and air with fire. Thus its motion is a second 
reason why that air is not condensed into water. 

But whenever a particle of air grows heavy/ the warmth 5 
in it is squeezed out into the upper region and it sinks, and 
other particles in turn are carried up together with the fiery 
exhalation. Thus the one region is always full of air and 
the other of fire, and each of them is perpetually in a state 
of change. 

So much to explain why clouds are not formed and why i 
the air is not condensed into water, 4 and what account must 
be given of the space between the stars and the earth, and 
what is the body that fills it. 

As for the heat derived from the sun, the right place for 
a special and scientific account of it is in the treatise about 
sense, 5 since heat is an affection of sense, but we may now 15 
explain how it can be produced by the heavenly bodies 
which are not themselves hot. 

1 Read ^vxpov in 1. 27 with E l and cod. Par. suppl. 314, cp. 360* 
22 sq. 

2 i.e. up to the height of the highest mountains. But cp. with the 
whole passage 36i a 22, 373*23, 34o !l 25 above. 

3 i.e. becomes drfus. * In the upper air. 
5 No such account is to be found in the De Sens it. 


We see that motion is able to dissolve and inflame the 
air; indeed, moving bodies are often actually found to melt. 
Now the sun s motion alone is sufficient to account for the 

20 origin of terrestrial warmth and heat. For a motion that is 
to have this effect must be rapid and near, and that of the 
stars is rapid but distant, while that of the moon is near but 
slow, whereas the sun s motion combines both conditions in 
a sufficient degree. That most heat should be generated 

25 where the sun is present l is easy to understand if we con 
sider the analogy of terrestrial phenomena, for here, too, it 
is the air that is nearest to a thing in rapid motion which 
is heated most. This is just what we should expect, as it 
is the nearest air that is most dissolved by the motion of 
a solid body. 

30 This then is one reason why heat reaches our world. 
Another is that the fire surrounding the air is often scattered 
by the motion of the heavens and driven downwards in spite 
of itself. 

Shooting-stars further suffice to prove that the celestial 
sphere is not hot or fiery : for they do not occur in that 
upper region but below : yet the more and the faster 2 

35 a thing moves, the more apt it is to take fire. 3 Besides, the 
sun, which most of all the stars is considered to be hot, is 
really white and not fiery in colour. 

34l b Having determined these principles let us explain the 4 
cause of the appearance in the sky of burning flames and of 
shooting-stars, and of torches , and * goats , as some 
people call them. All these phenomena are one and the 
5 same thing, and are due to the same cause, the difference 
between them being one of degree. 

The explanation of these and many other phenomena is 
this. When the sun warms the earth the evaporation which 
takes place is necessarily of two kinds, not of one only as 
some think. 4 One kind is rather of the nature of vapour, 

1 i. e. by day. 

Read TO. paXXov KivovjMfva Knl darrov fKnvpovrai GIITTOV in 1. 34 with 
JF and the lemma in Philoponus. 

3 And the outer sphere moves fastest. 

4 Perhaps Plato, Timaeus, 56 D. 

BOOK I. 4 34i b 

the other of the nature of a windy exhalation. That which 
rises from the moisture contained in the earth and on its 
surface is vapour, while that rising from the earth itself, ic 
which is dry, is like smoke. Of these the windy exhalation, 
being warm, rises above the moister vapour, which is heavy 
and sinks below the other. Hence the world surrounding 
the earth is ordered as follows. First below the circular 
motion comes the warm and dry element, which we call fire, 
for there is no word fully adequate to every state of the fumid 15 
evaporation : but we must use this terminology since this 
element is the most inflammable of all bodies. Below this 
comes air. We must think of what we just called fire as 
being spread round the terrestrial sphere on the outside like ^o 
a kind of fuel, so that a little motion often makes it burst 
into flame just as smoke does : for flame is the ebullition of 
a dry exhalation. 1 So whenever the circular motion stirs 
this stuff up in any way, it catches fire at the point at which 
it is most inflammable. The result differs according to the 
disposition and quantity of the combustible material. If 25 
this is broad and long, we often see a flame burning as 
in a field of stubble : if it burns lengthwise only, we sec 
what are called * torches and goats and shooting-stars. 
Now when the inflammable material is longer than it is 
broad sometimes it seems to throw off sparks as it burns. 30 
(This happens because matter catches fire at the sides in 
small portions but continuously with the main body.) Then 
it is called a goat . When this does not happen it is 
a torch*. But if the whole length of the exhalation is 
scattered in small parts and in many directions and in 
breadth and depth alike, we get what are called shooting- 
stars. 3 - 

The cause of these shooting-stars is sometimes the motion 
which ignites the exhalation. At other times the air is con- 342* 
densed by cold and squeezes out and ejects 2 the hot element ; 
making their motion look more like that of a thing thrown 
than like a running fire. For the question might be raised 

1 Cp. 340" 23. 

2 Read cfcdXt/Scrai *ai eorpiWai with JFHN and the lemma in 


whether the shooting of a star is the same thing as when 
5 you put an exhalation below a lamp and it lights the lower 
lamp from the flame above. For here too the flame passes 
wonderfully quickly and looks like a thing thrown, and 
not as if one thing after another caught fire. Or is a star 
when it shoots a single l body that is thrown ? Apparently 2 
both cases occur : sometimes it is like the flame from the 
lamp and sometimes bodies are projected by being squeezed 

10 out (like fruit stones from one s fingers) and so are seen to 
fall into the sea and on the dry land, both by night and by 
day when the sky is clear. They are thrown downwards 
because the condensation which propels them inclines 
downwards. Thunderbolts fall downwards for the same 

15 reason: their origin is never combustion but ejection under 
pressure, since naturally all heat tends upwards. 

When the phenomenon is formed in the upper region 3 it 
is due to the combustion of the exhalation. When it takes 
place at a lower level it is due to the ejection of the exhala 
tion by the condensing and cooling of the moister evapo- 

20 ration : for this latter as it condenses and inclines downward 
contracts, and thrusts out the hot element and causes it to 
be thrown downwards. The motion is upwards or down 
wards or sideways according to the way in which the 
evaporation lies, and its disposition in respect of breadth 
and depth. In most cases the direction is sideways because 

25 two motions are involved, a compulsory motion downwards 
and a natural motion upwards, and under these circum 
stances an object always moves obliquely. Hence the 
motion of shooting-stars is generally oblique. 

So the material cause of all these phenomena is the 
exhalation, the efficient cause sometimes the upper motion, 

30 sometimes the contraction and condensation of the air. 
Further, all these things happen below the moon. This is 
shown by their apparent speed, which is equal to that of 
things thrown by us ; for it is because they are close to us, 

1 Read roO atr<>0 nvos in 1. 7 with JF 2 HN Ol. (lemma). 

2 Om. dt in 1. 8 with all the MSS. 

3 Omit paXXoi/ and read > in 1. 17 with E and the lemma in 
Olympiodorus. /ifiXXoi/ and the superlative nywrdro) are explanations 

of ai O). 

BOOK I. 4 342 a 

that these latter seem far to exceed in speed the stars, the 
sun, and the moon. 

5 Sometimes on a fine night we see a variety of appearances 35 
that form in the sky : * chasms for instance and trenches 
and blood-red colours. These, too, have the same cause. 1 
For we have seen that the upper air condenses into an 
inflammable condition and that the combustion sometimes 
takes on the appearance of a burning flame, sometimes that 
of moving torches and stars. So it is not surprising that 5 
this same air when condensing should assume a variety of 
colours. For a weak light shining through a dense air, and 
the air when it acts as a mirror, will cause all kinds of 
colours to appear, but especially crimson and purple. For 
these colours generally appear when fire-colour and white 
are combined by superposition. Thus on a hot day, or 
through a smoky medium, the stars when they rise and set I0 
look crimson. The light will also create colours by reflection 
when the mirror is such as to reflect colour only and not 
shape. 2 

These appearances do not persist long, because the con 
densation of the air is transient. 

Chasms get their appearance of depth from light break- l r> 
ing out of a dark blue or black mass of air. When the 
process of condensation goes further in such a case we often 
find torches ejected. When the chasm contracts it 
presents the appearance of a trench V 5 

In general, white in contrast with black creates a variety 
of colours ; like flame, for instance, through a medium of 
smoke. But by day the sun obscures them, and, with the jo 
exception of crimson, the colours arc not seen at night 
because they are dark. 4 

1 As the phenomena described in c. 4. The obscurity of this chapter is 
due to the attempt to assimilate these phenomena of cloud coloration 
to the meteorites, c., of c. 4. Ar. seems entirely to neglect the most 
obvious causes of these <uo>umi, e.g. the sun, and obscures the fact 
that the phenomena of c. 4 are KaQ* VTTOITTIKTII , in the language of later 
writers, while those of c. 5 are *ar e/K/wo-iv. Cf. (Gilbert, -Meteor. 
Tlieorien d.g> . Altcrtums, pp. 594 sqq. 

2 Cp. 372* 29 sq. 

3 Read in 1. 17 o-wibv 8e fiodwos tiv<n TO) ^<r/Lta doKfl after Thurot. 

4 Read 6/zoxP" la " in 1. 20 with all the MSS. 

645-21 J3 


These then must be taken to be the causes of shooting- 
stars and the phenomena of combustion and also of the 
other transient appearances of this kind. 

25 Let us go on to explain the nature of comets and the milky < 
way , after a preliminary discussion of the views of others. 

Anaxagoras l and Democritus 2 declare that comets are 
a conjunction of the planets approaching one another and so 
appearing to touch one another. 

30 Some of the Italians called Pythagoreans 3 say that the 
comet is one of the planets, but that it appears at great 
intervals of time and only rises a little above the horizon. 
This is the case with Mercury too; because it only rises 
a little above the horizon it often fails to be seen and con- 

35 sequently appears at great intervals of time. 

A view like theirs was also expressed by Hippocrates of 
343 a Chios and his pupil Aeschylus. 4 Only they say that the 
tail does not belong to the comet itself, but is occasionally 
assumed by it on its course in certain situations, when our 
sight is reflected to the sun from the moisture attracted 
by the comet. It appears at greater intervals than the 
5 other stars because it is slowest to get clear of the sun 
and has been left behind by the sun to the extent 
of the whole of its circle before it reappears at the 
same point. It gets clear of the sun both towards the 
north and towards the south. In the space between the 
tropics it does not draw water to itself because that region 

10 is dried up by the sun on its course. When it moves 
towards the south it has no lack of the necessary moisture, 
but because the segment of its circle which is above the 
horizon is small, and that below it many times as large, it 
is impossible for the sun to be reflected to our sight, either 

15 when it approaches the southern 5 tropic, or at the summer 
solstice. Hence in these regions it does not develop a tail 
at all. But when it is visible in the north it assumes a tail 
because the arc above the horizon is large and that below it 

1 Diels, Frag. d. Vorsokratiker, 46 A Si. 

2 Ibid. 55 A 92. 3 Diels, 30. 5. 4 Ibid. 

5 Read vorw for T/JOTTIKW in 1. 14 with E l and perhaps Al. (The 
lemma in Philoponus has t/oriw 

BOOK I. 6 343 a 

small. For under these circumstances there is nothing to 
prevent our vision from being reflected to the sun. 20 

These views involve impossibilities, some of which are 
common to all of them, while others are peculiar to some 

This is the case, first, with those who say that the comet 
is one of the planets. For all the planets appear in the 
circle of the zodiac, whereas many comets have been seen 35 
outside that circle. Again more comets than one have 
often appeared simultaneously. Besides, if their tail is due 
to reflection, as Aeschylus and Hippocrates say, this planet 
ought sometimes to be visible without a tail since, as they 
say, it does not possess a tail in every place in which it 30 
appears. But, as a matter of fact, no planet has been ob 
served besides the five. And all of them are often visible 
above the horizon together at the same time. Further, 
comets are often found to appear, as well when all the 
planets are visible as when some are not, but are obscured 
by the neighbourhood of the sun. Moreover the statement 35 
that a comet only appears in the north, with the sun at the 
summer solstice, 1 is not true either. The great comet which 343 b 
appeared at the time of the earthquake in Achaea 2 and the 
tidal wave rose due west ; and many have been known 
to appear in the south. Again in the archonship of 
Euclees, son of Molon, at Athens 1 there appeared a comet 5 
in the north in the month Gamelion, 1 the sun being about 
the winter solstice. Yet they themselves admit that re 
flection over so great a space is an impossibility. 

An objection that tells equally against those who hold 
this theory and those who say that comets are a coalescence 
of the planets is, first, the fact that some of the fixed stars 
too get a tail. For this we must not only accept the 10 
authority of the Egyptians who assert it, but we have our 
selves observed the fact. For a star in the thigh of the Dog 
had a tail, though a faint one. If you fixed your sight on 

1 Cp. b 9. This condition was not stated in a 10 sq. Thurot would in 
troduce it there by emendation. Probably Aristotle is at fault and not 
the text. 

2 Cp. b 18, 344 b 34, 368 b 6. The date is 373-2 B. c. 

3 427-6 B.C. 4 Jan.- Feb. 

B 2 


it its light was dim, but if you just glanced at it, 1 it appeared 

15 brighter. Besides, all the comets that have been seen in 
our day have vanished without setting, gradually fading 
away above the horizon ; and they have not left behind 
them either one or more stars. For instance the great 
comet we mentioned before 2 appeared to the west in 
winter in frosty weather when the sky was clear, in the 

20 archonship of Asteius. On the first day it set before the 
sun and was then not seen. On the next day it was seen, 
being ever so little behind the sun and immediately setting. 
But its light extended over a third part of the sky like 
a leap, so that people called it a path . This comet re- 

25 ceded as far as Orion s belt and there dissolved. Democritus 
however, insists upon the truth of his view and affirms that 
certain stars have been seen when comets dissolve. But on 
his theory this ought not to occur occasionally but always. 
Besides, the Egyptians affirm that conjunctions of the 
planets with one another, and with the fixed stars, take 

30 place, and we have ourselves observed Jupiter coinciding 15 
with one of the stars in the Twins and hiding it, and yet no 
comet was formed. Further, we can also give a rational 
proof of our point. It is true that some stars seem to be bigger 
than others, yet each one by itself looks indivisible. Con- 

35 sequently, just as, if they really had been indivisible, their 

conjunction could not have created any greater magnitude, so 

344 a now that they are not in fact indivisible but look as if 

they were, their conjunction will not make them look any 


Enough has been said, without further argument, to show 
that the causes brought forward to explain comets are false. 

5 We consider a satisfactory explanation of phenomena in- 7 
accessible to observation to have been given when our 
account of them is free from impossibilities. The observa 
tions before us 4 suggest the following account of the 

1 The peripheral parts of the retina are more sensitive to illumination 
than the central. Wundt, Phys.- Psych?, ii. 181, 502. 

2 b i. s Omitting dis in 1. 31 with EJFHN Al Ph Ol. 

4 vrroKfiTdi (1. 8) ... dia8f)op.ds (1. 15) is a parenthesis. The apodosis 
of the main sentence is do-Dyp roOro yiyvtrw. (1. 20). 

BOOK I. 7 344 a 

phenomena we are now considering. We know that the 
dry and warm exhalation is the outermost part of the 10 
terrestrial world which falls below the circular motion. It, 
and a great part of the air that is continuous with it below, 
is carried round the earth by the motion of the circular 
revolution. In the course of this motion it often ignites 
wherever it may happen to be of the right consistency, and 
this we maintain to be the cause of the shooting of 15 
scattered stars . We may say, then, that a comet is 
formed when the upper motion l introduces into a gathering 
of this kind a fiery principle not of such excessive strength 
as to burn up much of the material quickly, nor so weak as 
soon to be extinguished, but stronger and capable of 
burning up much material, and when exhalation of the 20 
right consistency rises from below and meets it. The kind 
of comet varies according to the shape which the exhalation 
happens to take. If it is diffused equally on every side the 
star is said to be fringed, if it stretches out in one direction 
it is called bearded. We have seen that when a fiery 
principle of this kind moves we seem to have a shooting- 25 
star : similarly when it stands still we seem to have a star 
standing still. We may compare these phenomena to 
a heap or mass of chaff into which a torch is thrust, or 
a spark thrown. That is what a shooting-star is like. The 
fuel is so inflammable that the fire runs through it quickly 
in a line. Now if this fire were to persist instead of running 30 
through the fuel and perishing away, its course through the 
fuel would stop at the point where the latter was densest, 
and then the whole might begin to move. Such is a comet 
like a shooting-star that contains its beginning and end in 

When the matter begins to gather in the lower region in 
dependently the comet appears by itself. But when the 35 
exhalation is constituted - by one of the fixed stars or the 
planets, owing to their motion, one of them becomes a comet. 
The fringe is not close to the stars themselves. Just as 344 b 

1 Omitting TW in 1. 16 with JHN, and Philoponus. 

2 345 a 7, b 34- 


haloes appear to follow the sun and the moon as they move, 1 
5 and encircle them, when the air is dense enough for them to 
form along under the sun s course, so too the fringe. It 
stands in the relation of a halo to the stars, except that the 
colour of the halo is due to reflection, whereas in the case of 
comets the colour is something that appears actually on 

Now when this matter gathers in relation to a star the 

10 comet necessarily appears to follow the same course as the 
star. But when the comet is formed independently it falls 
behind the motion of the universe, like the rest of the 
terrestrial world. It is this fact, that a comet often forms 
independently, 2 indeed oftener than round one of the 
regular stars, that makes it impossible to maintain that 

15 a comet is a sort of reflection, not indeed, as Hippocrates 
and his school say. 3 to the sun, but to the very star it is 
alleged to accompany in fact, a kind of halo in the pure 
fuel of fire. 4 

As for the halo we shall explain its cause later. 5 

The fact that comets when frequent c foreshadow wind 

20 and drought must be taken as an indication of their fiery 
constitution. For their origin is plainly due to the plentiful 
supply of that secretion. Hence the air is necessarily drier 
and the moist evaporation is so dissolved and dissipated by 
the quantity of the hot exhalation as not readily to con- 

25 dense into water. But this phenomenon too shall be 
explained more clearly later when the time comes to 
speak of the winds. So when there are many comets 
and they are dense, it is as we say, and the years 
are clearly dry and windy. When they are fewer and 
fainter this effect does not appear in the same degree, 

30 though as a rule the wind is found to be excessive either in 
duration or strength. For instance when the stone at 
Aegospotami fell out of the air it had been carried up by 

1 Omit TWV <"(TTpav in 1.4 with EJHN and the lemmata in Philoponus 
and Olympiodorus. 

2 Comma after 7io\AKt$- in 1. 16, with Philoponus. 

3 342 b 36. 4 Comma after KaQapu in 1. 14. 
6 iii. 2. 

6 Omit 01 in 1. 20 with the MSS., Alexander, and Philoponus. 

BOOK I. 7 344 b 

a wind and fell down in the daytime then too a comet 
happened to have appeared in the west. And at the time of 
the great comet l the winter was dry and north winds pre- 35 
vailed, and the wave was due to an opposition of winds. 
For in the gulf a north wind blew and outside it a violent 345 a 
south wind. Again in the archonship of Nicomachus 2 
a comet appeared for a few days about the- equinoctial 
circle (this one had not risen in the west), and simultaneously 
with it there happened the storm at Corinth. 5 

That there are few comets and that they appear rarely 
and outside the tropic circles 3 more than within them is 
due to the motion of the sun and the stars. 4 For this 
motion does not only cause the hot principle to be secreted 
but also dissolves it when it is gathering. But the chief 
reason is that most of this stuff collects in the region of the 
milky way. I0 

8 Let us now explain the origin, cause, and nature of the 
milky way. And here too let us begin by discussing the 
statements of others on the subject. 

(1) Of the so-called Pythagoreans 5 some say that this is the 
path of one of the stars that fell from heaven at the time of 15 
Phaethon s downfall. Others say that the sun used once to 
move in this circle and that this region was scorched or met 
with some other affection of this kind, because of the sun 
and its motion. 

But it is absurd not to see that if this were the reason the 
circle of the Zodiac ought to be affected in the same way, 
and indeed more so than that of the milky way, since not 20 
the sun only but all the planets move in it. We can see 
the whole of this circle (half of it being visible at any time 
of the night), but it shows no signs of any such affection G 
except where a part of it touches the circle of the milky 

(2) Anaxagoras, Democritus, and their schools say that 25 

1 Cp. 343 bi. 

2 341-40 B.C. Omit A6f)VT)aiv in 1. 2 with KJFHN. 

3 346 a 14- 4 344 a 35- 
6 Diels, 45 B. 37 ; 29. 10. 

6 Read Tr^ovB^ in 1. 23 with EFH Al. 


the milky way is the light of certain stars. For, they say, 
when the sun passes below the earth some of the stars are 
hidden from it. Now the light of those on which the sun 
shines is invisible, being obscured by the rays of the sun. 

30 But the milky way is the peculiar light of those stars 
which are shaded by the earth from the sun s rays. 

This, too, is obviously impossible. The milky way is 
always unchanged and among the same constellations (for 
it is clearly a greatest circle), 1 whereas, since the sun does 
not remain in the same place, what is hidden from it differs 

35 at different times. Consequently with the change of the 
sun s position the milky way ought to change its position 
345 b too : but we find that this does not happen. Besides, if 
astronomical demonstrations are correct and the size of the 
sun is greater than that of the earth and the distance of the 
stars from the earth many times greater than that of the 
sun (just as the sun is further from the earth than the 

5 moon), then the cone made by the rays of the sun would 
terminate at no great distance from the earth, and the 
shadow of the earth (what we call night) would not reach 
the stars. On the contrary, the sun shines on all the stars 
and the earth screens none of them. 

jo (3) There is a third theory about the milky way. Some 
say that it is a reflection of our sight to the sun, just as they 
say that the comet is.- 

But this too is impossible. For if the eye and the 
mirror and the whole of the object were severally at rest, 
then the same part of the image would appear at the same 
3 point in the mirror. But if the mirror and the object 
move, keeping the same distance from the eye which is at 
rest, but at different rates of speed and so :J not always at 
the same interval from one another, then it is impossible for 
the same image always to appear in the same part of the 
mirror. Now the constellations included in the circle of the 
milky way move ; and so does the sun, the object to which 

20 our sight is reflected ; but we stand still. And the distance 

1 346* 17 and note. 2 342 b 35 ; Diels, 30. 6. 

3 Reading rf . . . p;& in 1. 17 with E, Alexander (citation), and 

BOOK I. 8 345 

of those two from us is constant and uniform, but their 
distance from one another varies. For the Dolphin some 
times rises at midnight, sometimes in the morning. But in 
each case the same parts of the milky way are found near it. 
But if it were a reflection and not a genuine affection of 
these regions, this ought not to be the case. 

Again, we can see the milky way reflected at night in 25 
water and similar mirrors. But under these circumstances 
it is impossible for our sight to be reflected to the sun. 

These considerations show that the milky way is not the 
path of one of the planets, nor the light of imperceptible 
stars, nor a reflection. And those are the chief theories 30 
handed down by others hitherto. 

Let us recall our fundamental principle and then explain 
our views. We have already laid down l that the outermost 
part of what is called the air is potentially fire and that 
therefore when the air is dissolved by motion, there is 
separated off a kind of matter and of this matter we assert 
that comets consist. We must suppose that what happens 35 
is the same as in the case of the comets when the matter 
does not form independently but is formed by one of the 
fixed stars or the planets. Then these stars appear to be 
fringed, because matter of this kind follows their course. In 
the same way, a certain kind of matter follows the sun, 
and we explain the halo as a reflection from it when the 5 , 
air is of the right constitution. Now we must assume that 
what happens in the case of the stars severally happens in 
the case of the whole of the heavens and all the upper 
motion. For it is natural to suppose that, if the motion of 
a single star excites a flame, that of all the stars should 
have a similar result, 2 and especially in that region in which Ic 
the stars are biggest and most numerous and nearest to one 
another. Now the circle of the zodiac dissolves this kind 
of matter because of the motion of the sun and the planets, 

1 34o b 4-32. 

^ Fobes inserts after cVcpiTrtfcu (1. 9) the following words from FHN 
depare Koi dtaKpivdv dia TO rov KVK\OV p.tye6os, and the following lemmata 
from Ol. dvdyKTj Toivvv TU>V avTa>v p-fyiarav KVK\O)V p.u\iuT<i TI]V fj.(\\oi(T<iv 
TOi-To 7roirj(Tiv (popdv . . . \pf] yap TOVTO, Iva TroXAr) Kii-ijait /J fiia TO p.(yf6ot 
ytyvop.(vrj Kcil 7r\(iova ri]v (<i^u/ Trouya//. Al. Phil, seem to have had 
our text without these additions. 


and for this reason most comets are found outside the 
tropic circles. 1 Again, no fringe appears round the sun or 

15 moon : for they dissolve such matter too quickly to admit 
of its formation. But this circle in which the milky way 
appears to our sight is the greatest circle, 2 and its position 
is such that it extends far outside the tropic circles. Besides 
the region is full of the biggest and brightest constellations 

ao and also of what are called scattered stars (you have only 
to look to see this clearly). So for these reasons all this 
matter is continually and ceaselessly collecting there. 
A proof of the theory is this : In the circle itself the light 
is stronger in that half where the milky way is divided, and 
in it the constellations are more numerous and closer to one 

25 another than in the other half; which shows that the cause 
of the light is the motion of the constellations and nothing 
else. For if it is found in the circle in which there are 
most constellations and at that point in the circle at which 
they are densest and contain the biggest and the most 

30 stars, it is natural to suppose that they are the true cause 
of the affection in question. The circle and the constella 
tions in it may be seen in the diagram." The so-called 
1 scattered stars it is not possible to set down in the same 
way on the sphere because none of them have an evident 

1 345 a 6. 

2 It is difficult to understand what is meant by the greatest circle . 
Cf. 345 a 33 and 346 b 6. The meaning cannot be a great circle of the 
celestial sphere in the ordinary sense; for, (i) this would not justify 
the article here and in 346 b 6, (2) the fact that a circle is a great 
circle in the ordinary sense does not involve any part of it, except 
the points at which it cuts the equator, moving fastest ; unless it 
happens to be the equator, and Ar. does not suppose that the milky 
way is. Vicomercatus suggests that ^eyta-ros refers to the breadth of the 
band, but this is unsatisfactory. \Ve are forced to assume that Ar. was 
thinking in a confused way of the outermost sphere, that of the fixed 
stars. Every point of this does, of course, move faster than every 
corresponding point on an interior sphere. This will also justify the 
article. It also explains 345* 33 : the milky way is in the sphere of 
the fixed stars and cannot therefore move about, as the hypothesis would 
require . It is true that the theory still does not work, even on its own 
presuppositions. But it could only work if we supposed the milky way 
to rotate on an axis at right angles to its own plane ; and Ar. certainly 
did not think it did that. 

3 Aristotle must be supposed to have illustrated his theory here by 
a diagram of the milky way, but the Greek commentators have not 
preserved any tradition of the particular diagram used. 

BOOK I. 8 346 

permanent position ; but if you look up to the sky the 
point is clear. For in this circle alone are the intervals full 35 
of these stars : in the other circles there are obvious gaps. 
Hence if we accept the cause assigned for the appearance 
of comets as plausible we must assume that the same kind 
of thing holds good of the milky way. For the fringe 
which in the former case is an affection of a single star here 
forms in the same way in relation to a whole circle. So if 5 
we are to define the milky way we may call it * a fringe 
attaching to the greatest circle, and due to the matter 
secreted . This, as we said before, 1 explains why there 
are few comets and why they appear rarely ; it is because 
at each revolution of the heavens this matter has always 
been and is always being separated off and gathered into 
this region. 

We have now explained the phenomena that occur in that I0 
part of the terrestrial world which is continuous with the 
motions of the heavens, namely, shooting-stars and the 
burning flame, comets and the milky way, these being 
the chief affections that appear in that region. 15 

9 Let us go on to treat of the region which follows next 
in order after this and which immediately surrounds the 
earth. It is the region common to water and air, and the 
processes attending the formation of water above 2 take 
place in it. We must consider the principles and causes 
of all these phenomena too as before. 

The efficient and chief and first cause is the circle in 20 
which the sun moves. 3 For the sun as it approaches or 
recedes, obviously causes dissipation and condensation and 
so gives rise to generation and destruction. Now the earth 
remains but the moisture surrounding it is made to evaporate 
by the sun s rays and the other heat from above, and rises. 25 
But when the heat which was raising it leaves it, in part 
dispersing to the higher region, in part quenched through 
rising so far into the upper air, then the vapour cools 

1 345 a .7-. 

2 As distinguished from its formation on and under the earth, cc. 13- 
ii. 3. 

3 Cp. De Gen. et Corr. ii. 10; esp. 336 b 15 sqq. 


because its heat is gone and because the place is cold, and 
30 condenses again and" turns from air into water. And after 
the water has formed it falls down again to the earth. 1 

The exhalation of water is vapour : air condensing into 
water is cloud. Mist is what is left over when a cloud 
condenses into water, and is therefore rather a sign of fine 
weather than of rain ; for mist might be called a barren 

35 So we get a circular process that follows the course of 
347 a the sun. For according as the sun moves to this side or 
that, 2 the moisture in this process rises or falls. We must 
think of it as a river flowing up and down in a circle and 
made up partly of air, partly of water. When the sun is 
near, the stream of vapour flows upwards ; when it recedes, 
5 the stream of water flows down : and the order of sequence, 
at all events, in this process always remains the same. So 
if Oceanus had some secret meaning in early writers, 
perhaps they may have meant this river that flows in 
a circle about the earth. 1 5 

So the moisture is always raised by the heat and descends 

10 to the earth again when it gets cold. These processes and, in 

some cases, their varieties are distinguished by special 

names. When the water falls in small drops it is called 

a drizzle ; when the drops are larger it is rain. 

Some of the vapour that is formed by day does not rise 10 
high because the ratio of the fire that is raising it to the 

15 water that is being raised is small. When this cools and 
descends at night it is called dew and hoar-frost. When 
the vapour is frozen before it has condensed to water again 
it is hoar-frost ; and this appears in winter and is commoner 
in cold places. It is dew when the vapour has condensed 
into water and the heat is not so great as to dry up the 

20 moisture that has been raised, nor the cold sufficient (owing 
to the warmth of the climate or season) for the vapour itself 
to freeze. For dew is more commonly found when the 
season or the place is warm, whereas the opposite, as has 

1 Cp. 359 b 34sq. 

2 i.e. north and south on the ecliptic; cp. 361*4 sq. 

3 Cp. 359 b 34- 

BOOK I. 10 347 a 

been said, is the case with hoar-frost. For obviously 
vapour is warmer than water, having still the fire that 
raised it : consequently more cold is needed to freeze it. 25 

Both dew and hoar-frost are found when the sky is clear 
and there is no wind. For the vapour could not be raised 
unless the sky were clear, and if a wind were blowing 
it could not condense. 

The fact that hoar-frost is not found on mountains 
contributes to prove that these phenomena occur because 
the vapour does not rise high. One reason for this is that 30 
it rises from hollow and watery places, so that the heat 
that is raising it, bearing as it were too heavy a burden 
cannot lift it to a great height but soon lets it fall again. 
A second reason is that the motion of the air is more 
pronounced at a height, and this dissolves a gathering of 
this kind. 

Everywhere, except in Pontus, dew is found with south 35 
winds and not with north winds. There the opposite is the 
case and it is found with north winds and not with south. 
The reason is the same as that which explains why dew 347 b 
is found in warm weather and not in cold. For the south 
wind brings warm, and the north, wintry weather. For the 
north wind is cold and so quenches the heat of the evapora 
tion. But in Pontus the south wind does not bring warmth 
enough to cause evaporation, whereas the coldness of the 5 
north wind concentrates the heat by a sort of recoil, so 
that there is more evaporation and not less. 1 This is a thing 
which we can often observe in other places too. Wells, for 
instance, give off more vapour 2 in a north than in a south 
wind. Only :! the north winds quench the heat before any 
considerable quantity of vapour has gathered, while in 10 
a south wind the evaporation is allowed to accumulate. 

Water, 4 once formed, does not freeze on the surface of 
the earth, in the way that it docs in the region of the 

1 As you might expect from the coldness of the wind. 

2 Read ar^a in 1. 8 with the IVISS. 

3 i.e. in places other than Pontus. 

4 As contrasted with vapour. Ar. is thinking merely of the lack of 
an analogue to hail. 


From the latter there fall three bodies condensed by cold, II 
namely rain, snow, hail. Two of these correspond to the 
phenomena on the lower level and are due to the same 

15 causes, differing from them only in degree and quantity. 

Snow and hoar-frost are one and the same thing, and so 
are rain and dew : only there is a great deal of the former 
and little of the latter. For rain is due to the cooling 
of a great amount of vapour, for the region from which 
and the time during which the vapour is collected are 

20 considerable. But of dew there is little : for the vapour 
collects for it in a single day and from a small area, as its 
quick formation and scanty quantity show. 

The relation of hoar-frost and snow is the same : when 
cloud freezes there is snow, when vapour freezes there 
is hoar-frost. Hence snow is a sign of a cold season or 

25 country. For a great deal of heat is still present and 
unless the cold were overpowering it the cloud would not 
freeze. For there still survives in it a great deal of the heat 
which l caused the moisture to rise as vapour from the 

Hail on the other hand is found in the upper region, but 
the corresponding phenomenon in the vaporous region near 

30 the earth is lacking. For, as we said, to snow in the upper 
region corresponds hoar-frost in the lower, and to rain in 
the upper region, dew in the lower. But there is nothing 
here to correspond to hail in the upper region. Why this 
is so will be clear when we have explained the nature 
of hail. 

But we must go on to collect the facts bearing on the ii> 
35 origin of it, both those which raise no difficulties and those 

which seem paradoxical. 

348* Hail is ice, and water freezes in winter ; yet hailstorms 
occur chiefly in spring and autumn and less often in the 
late summer, but rarely in winter and then only when the 
cold is less intense. And in general hailstorms occur in 
warmer, and snow in colder places. Again, there is 
5 a difficulty about water freezing in the upper region. It 

1 Omit nvpos in 1. 28 with E 1 and (apparently) Alexander. 

BOOK I. 12 348 a 

cannot have frozen before becoming water : and water 
cannot remain suspended in the air for any space of time. 
Nor can we say that the case is like that of particles of 
moisture which are carried up owing to their small size 
and rest on the air (the water swimming on the air just as 10 
small particles of earth and gold often swim on water). In 
that case large drops arc formed by the union of many 
small, and so fall down. This cannot take place in the case 
of hail, since solid bodies cannot coalesce like liquid ones. 
Clearly then drops of that size were suspended in the air 
or else they could not have been so large when frozen. 

Some 1 think that the cause and origin of hail is this. 
The cloud is thrust up into the upper atmosphere, which is 15 
colder because the reflection of the sun s rays from the 
earth ceases there, 2 and upon its arrival there the water 
freezes. They think that this explains why hailstorms are 
commoner in summer and in warm countries ; the heat is 
greater and it thrusts the clouds further up from the earth. 
But the fact is that hail does not occur at all at a great 2 o 
height : yet it ought to do so, on their theory, just as 
we see that snow falls most on high mountains. Again 
clouds have often been observed moving with a great noise 
close to the earth, terrifying those who heard and saw 25 
them as portents of some catastrophe. Sometimes, too, 
when such clouds have been seen, without any noise, there 
follows a violent hailstorm, and the stones are of incredible 
size, and angular in shape. This shows that they have not 
been falling for long and that they were frozen near to the 
earth, and not as that theory would have it. Moreover, 30 
where the hailstones are large, the cause of their freezing 
must be present in the highest degree : for hail is ice as 
every one can see. Now those hailstones are large which 
are angular in shape. And this shows that they froze close 
to the earth, for those that fall far are worn away by the 35 
length of their fall and become round and smaller in 

It clearly follows that the congelation does not take 348 b 

1 i.e. Anaxagoras, cp. b 12, Diels, 46 A 85. 

2 Cp. 340*27 sqq. 


place because the cloud is thrust up into the cold upper 

Now we see that warm and cold react upon one another 
by recoil. Hence in warm weather the lower parts of 
5 the earth are cold and in a frost they are warm. The 
same thing, we must suppose, happens in the air, so that in 
the warmer seasons the cold is concentrated by the sur 
rounding heat and causes the cloud to go over into water 
suddenly. 1 (For this reason rain-drops are much larger on 
warm days than in winter, and showers more violent. 

10 A shower is said to be more violent in proportion as the 
water comes down in a body, and this happens when the 
condensation takes place quickly, though this is just the 
opposite of what Anaxagoras says. He says that this happens 
when the cloud has risen into the cold air ; whereas we say 
that it happens when the cloud has descended into the warm 
air, and that the more the further the cloud has descended). 

15 But when the cold has been concentrated within still more 
by the outer heat, it freezes the water it has formed and 
there is hail. We get hail when the process of freezing is 
quicker than the descent of the water. For if the water 
falls in a certain time and the cold is sufficient to freeze it 

20 in less, there is no difficulty about its having frozen in the 
air, provided that the freezing takes place in a shorter time 
than its fall. The nearer to the earth, and the more 
suddenly, this process takes place, the more violent is the 
rain that results and the larger the raindrops and the 

25 hailstones because of the shortness of their fall. For 
the same reason large raindrops do not fall thickly. Hail 
is rarer in hummer than in spring and autumn, though 
commoner than in winter, because the air is drier in 
summer, whereas in spring it is still moist, and in autumn 
it is beginning to grow moist. It is for the same reason 
that hailstorms sometimes occur in the late summer as we 
have said. 2 
3 o The fact that the water has previously been warmed 

1 Omit ore 8c ^aXn^ai/ in 1. 8, with all the MSS. except N corr. ore 
/icV is answered by ornv 6 b i5 below and the intervening lines dtb 
KOI . . . 6 rai/ p.a\i<TTd are parenthetical and should be printed accordingly. 

BOOK I. 12 348 

contributes to its freezing quickly : for so it cools sooner. 
Hence many people, when they want to cool hot water l 
quickly, begin by putting it in the sun. So the inhabitants 
of Pontus when they encamp on the ice to fish (they cut 35 
a hole in the ice and then fish) pour warm water round 
their reeds that it may freeze the quicker, for they use the 349* 
ice like lead to fix the reeds. Now it is in hot countries 
and seasons that the water which forms soon grows warm. 

It is for the same reason that rain falls in summer and 
not in winter in Arabia and Ethiopia too, and that in 5 
torrents and repeatedly on the same day. For the con 
centration or recoil due to the extreme heat of the country 
cools the clouds quickly. 

So much for an account of the nature and causes of rain, 10 
dew, snow, hoar-frost, and hail. 

13 Let us explain the nature of winds, and all windy 
vapours, also of rivers and of the sea. But here, too, we 
must first discuss the difficulties involved : for, as in other 
matters, so in this no theory has been handed down to us 15 
that the most ordinary man could not have thought of. 

Some 2 say that what is called air, when it is in motion 
and flows, is wind, and that this same air when it condenses 
again becomes cloud and water, implying that the nature 
of wind and water is the same. So they define wind as 
a motion of the air. Hence some, wishing to say a clever 20 
thing, assert that all the winds are one wind, because 
the air that moves is in fact all of it one and the 
same ; they maintain that the winds appear to differ owing 
to the region from which the air may happen to flow :i on 
each occasion, but really do not differ at all. This is just 25 
like thinking that all rivers are* one and the same river, and 
the ordinary unscientific view is better than a scientific 
theory like this. If all rivers flow from one source, and 
the same is true in the case of the winds, there might be 
some truth in this theory ; but if it is no more true in the 30 
one case than in the other, this ingenious idea is plainly 

1 Read TO 6tpfi6v in 1. 33 with all the MSS. except F corr. 

2 Hippocrates Trepi <u<r&>j> (Opp., vol. i, 571. 12, ed. Kiihn). 

3 Read ptwv in 1. 24 with the MSS. 


false. What requires investigation is this : the nature of 
wind and how it originates, its efficient cause and whence 
they derive their source ; whether one ought to think of 
the wind as issuing from a sort of vessel and flowing until 

35 the vessel is empty, as if let out of a wineskin, or, as 
349 b painters represent the winds, as drawing their source from 

We find analogous views about the origin of rivers. 1 
It is thought that the water is raised by the sun and 
descends in rain and gathers below the earth and so flows 
from a great reservoir, all the rivers from one, or each 

5 from a different one. No water at all is generated, but the 
volume of the rivers 2 consists of the water that is gathered 
into such reservoirs in winter. Hence rivers are always 
fuller in winter than in summer, and some are perennial, 
others not. Rivers are perennial where the reservoir is large 

i and so enough water has collected in it to last out and not 
be used up before the winter rain returns. Where the 
reservoirs are smaller there is less water in the rivers, and 
they are dried up and their vessel empty before the fresh 
rain comes on. 

15 But if any one will picture to himself a reservoir adequate 
to the water that is continuously flowing day by day, and 
consider the amount of the water, it is obvious that a 
receptacle that is to contain all the water that flows in the 
year would be larger than the earth, or, at any rate, not much 

20 Though it is evident that many reservoirs of this kind do 
exist in many parts of the earth, yet it is unreasonable for 
any one to refuse to admit that air becomes water in the 
earth for the same reason as it does above it. If the cold 
causes the vaporous air to condense into water above the 
earth we must suppose the cold in the earth to produce 

25 this same effect, and recognize that there not only exists in 
it and flows out of it actually formed water, but that water 
is continually forming in it too. 

1 Cp. Anaxagoras, Burnet, Early Greek Philosophy , 135 = Diels, 
46 A. 42 5. 
? J\ea4 TO ro)v in 1. 7 with ] (TOVTWV E). 

BOOK I. 13 349 b 

Again, even in the case of the water that is not being 
formed from day to day but exists as such, we must not 
suppose as some do that rivers have their source in definite 30 
subterranean lakes. On the contrary, just as above the 
earth small drops form and these join others, till finally the 
water descends in a body as rain, so too we must suppose 
that in the earth the water at first trickles together little 
by little, and that the sources of the rivers drip, as it were, 
out of the earth and then unite. This is proved by facts. 35 
When men construct an aqueduct they collect the water in 350* 
pipes and trenches, as if the earth in the higher ground 
were sweating the water out. Hence, too, the head-waters 
of rivers are found to flow from mountains, and from the 
greatest mountains there flow the most numerous and 
greatest rivers. Again, most springs are in the neighbour- 5 
hood of mountains and of high ground, whereas if we 
except rivers, water rarely appears in the plains. For 
mountains and high ground, suspended 1 over the country 
like a saturated sponge, make the water ooze out and trickle 
together in minute quantities but in many places. They 
receive a great deal of water falling as rain (for it makes no 10 
difference whether a spongy receptacle is concave and turned 
up or convex and turned down : in either case it will contain 
the same volume of matter) and they also cool the vapour 
that rises and condense it back into water. 

Hence, as we said, we find that the greatest rivers flow 
from the greatest mountains. This can be seen by looking r^ 
at itineraries : what is recorded in them consists either of 
things which the writer has seen himself or of such as he 
has compiled after inquiry from those who have seen 

In Asia we find that the most numerous and greatest 
rivers flow from the mountain called Parnassus, 2 admittedly >o 
the greatest of all mountains towards the south-east. When 
you have crossed it you see the outer ocean/ 5 the further 
limit of which is unknown to the dwellers in our world. 

1 Read cirucpfpapfvtH in 1. 8 with EJF 2 HN. 

2 Paropamisus or Hindu Kush. 

3 Indian Ocean. 

C 2 


Besides other rivers there flow from it the Bactrus, 1 the 
Choaspes, 2 the Araxes : 3 from the last a branch separates 

25 off and flows into lake Maeotis 4 as the Tanais. 5 From it, 
too, flows the Indus, the volume of whose stream is greatest 
of all rivers. From the Caucasus flows the Phasis/ 5 and 
very many other great rivers besides. Now the Caucasus 
is the greatest of the mountains that lie to the north-east, 

30 both as regards its extent and its height. A proof of its 
height is the fact that it can be seen from the so-called 
deeps 7 and from the entrance to the lake. 8 Again, the 
sun shines on its peaks for a third part of the night before 
sunrise and again after sunset. Its extent is proved by the 
fact that though it contains many inhabitable regions which 
are occupied by many nations and in which there are said 

35 to be great lakes, yet they say that all these regions are 
35O b visible up to the last peak. 9 From Pyrene 10 (this is 
a mountain towards the west in Celtice) there flow the 
Istrus n and the Tartessus. 12 The latter flows outside the 
pillars, 13 while the Istrus flows through all Europe into the 
Euxine. Most of the remaining rivers flow northwards 
5 from the Hercynian mountains u , which are the greatest in 
height and extent about that region. In the extreme north, 
beyond furthest Scythia, are the mountains called Rhipae. 15 
The stories about their size are altogether too fabulous : 
however, they say that the most and (after the Istrus) the 

10 greatest rivers flow from them. So, too, in Libya there flow 
from the Aethiopian mountains the Aegon and the Nyses ; 16 
and from the so-called Silver Mountain the two greatest 
of named rivers, the river called Chremetes n that flows into 

1 Balch-ab. a Kunar. 

3 A. probably means the Oxus or Amu-Darya. 

4 Sea of Azov. 5 Don. 6 Rion. 
7 Cp. 35i a ii. 8 Maeotis. 

9 This is unintelligible : our text, though it goes back to Alexander, 
must be corrupt. 
10 Pyrenees. n Danube. 12 Baetis or Guadalquivir. 

13 Of Heracles. 

14 The mountains of Bohemia, Silesia, Moravia, and northern 

16 A mythical northern range to which no definite locality can be 

6 Read Nvv n s in 1. 12 with the MSS. 

17 Sagiet el Hamra. 

BOOK I. 13 350 

the outer ocean, and the main source of the Nile. Of the 15 
rivers in the Greek world, the Achelous flows from Pindus, 
the Inachus from the same mountain ; the Strymon, the 
Nestus, and the Hebrus all three from Scombrus ; many 
rivers, too, flow from Rhodope. 

All other rivers would be found to flow in the same way, 
but we have mentioned these as examples. Even where 20 
rivers flow from marshes, the marshes in almost every case 
are found to lie below mountains or gradually rising ground. 

It is clear then that we must not suppose rivers to originate 
from definite reservoirs: for the whole earth, we might 
almost say, would not be sufficient (any more than the 25 
region of the clouds would be) l if we were to suppose that 
they were fed by actually existing water only and it were 
not the case that as some water passed out of existence 
some more came into existence, but rivers always drew their 
stream from an existing store. Secondly, the fact that 
livers rise at the foot of mountains proves that a place 
transmits the water it contains by^ gradual percolation of 
many drops, little by little, and that this is how the sources 
of rivers originate. However, there is nothing impossible 30 
about the existence of such places containing a quantity of 
water like lakes : only they cannot be big enough to pro 
duce the supposed effect. To think that they are is just as 
absurd as if one were to suppose that rivers drew all their 
water from the sources we see (for most rivers do flow from 
springs). So it is no more reasonable to suppose those 35 
lakes to contain the whole volume of water than these 

That there exist such chasms and cavities in the earth we 35i a 
are taught by the rivers that are swallowed up. They are 
found in many parts of the earth : in the Peloponnesus, for 
instance, there are many such rivers in Arcadia. The 
reason is that Arcadia is mountainous and there are no 
channels from its valleys to the sea. So these places get 5 
full of water, and this, having no outlet, under the pressure 
of the water that is added above, finds a way out for itself 

1 i. e. any more than the region of clouds could be supposed to 
contain ready-made all the water that falls as rain. 


underground. In Greece this kind of thing happens on 
quite a small scale, but the lake at the foot of the Caucasus, 1 
which the inhabitants of these parts call a sea, is consider- 

10 able. 2 Many great rivers fall into it and it has no visible 
outlet but issues below the earth off the land of the 
Coraxi 3 about the so-called deeps of Pontus . This is 
a place of unfathomable depth in the sea : at any rate no 
one has yet been able to find bottom there by sounding. 
At this spot, about three hundred stadia from land, there 

15 comes up sweet water over a large area, not all of it together 
but in three places. And in Liguria a river 4 equal in size 
to the Rhodanus 5 is swallowed up and appears again else 
where : the Rhodanus being a navigable river. 

The same parts of the earth are not always moist or dry, 14 

20 but they change according as rivers come into existence and 
dry up. And so the relation of land to sea changes too and 
a place docs not always remain land or sea throughout all 
time, but where there was dry land there comes to be sea, and 
where there is now sea, there one day comes to be dryland. 

25 But we must suppose these changes to follow some order 
and cycle. The principle and cause of these changes is 
that the interior of the earth grows and decays, like the 
bodies of plants and animals. Only in the case of these 
latter the process does not go on by parts, but each of them 

30 necessarily grows or decays as a whole, whereas it does go 
on by parts in the case of the earth. Here the causes are 
cold and heat, which increase and diminish on account of 
the sun and its course. It is owing to them that the parts 
of the earth come to have a different character, that some 
parts remain moist for a certain time, and then dry up and 

35 grow old, while other parts in their turn are filled with life 

1 Caspian Sea. 

2 fyavfpa (1. 9) is certainly wrong it makes indifferent sense and is 
omitted by all the MSS. except S rec. Thurot thinks that a word 
(such as nfydXtj) or words expressing the contrast to /MIK/JU above are 
wanted, but this is not certain. 

3 On the east coast of the Black Sea, about the modern Abkasia. 

4 Perhaps the Eridanus (Po). Pliny alleges (falsely) that it flows 
underground (Pliny iii. 16). 

6 Rhone. 

BOOK I. 14 35i a 

and moisture. Now when places become drier the springs 
necessarily give out, and when this happens the rivers first 35l b 
decrease in size and then finally become dry ; and when 
rivers change and disappear in one part and come into 
existence correspondingly in another, the sea must needs be 

If the sea was once pushed out by rivers and encroached 5 
upon the land anywhere, it necessarily leaves that place dry 
when it recedes ; again, if the dry land has encroached on 
the sea at all by a process of silting set up by the rivers 
when at their full, the time must come when this place will 
be flooded again. 1 

But the whole vital process of the earth takes place so 
gradually and in periods of time which are so immense 
compared with the length of our life, that these changes are 10 
not observed, and before their course can be recorded from 
beginning to end whole nations perish and are destroyed. 
Of such destructions the most utter and sudden are due to 
wars ; but pestilence or famine cause them too. Famines, 
again, are either sudden and severe or else gradual. In the 15 
latter case the disappearance of a nation is not noticed 
because some leave the country while others remain ; and 
this goes on until the land is unable to maintain any 
inhabitants at all. So a long period of time is likely to 
elapse from the first departure to the last, and no one ao 
remembers and the lapse of time destroys all record even 
before the last inhabitants have disappeared. In the same 

1 Read a comma after cTrXtuvafcv in 1. 6, dmoivav with EJ 2 FHN, 
and 7r\r]dvov(n. The version given implies this line of thought : rivers 
fall into the sea at A and push it out (by silting) so that it floods the 
land at B ; when those rivers dry up the sea will recede from B. 
Again, a river fills up its estuary with silt and so land encroaches on 
the sea; when the river dries up the sea will return. 

The two orrov clauses are concerned with one and the same process, 
but the first considers the effect on the place 2>\ the second the effect 
on the place A. 

The general principle seems to be that when wet predominates in 
a place rivers rise there : this makes the sea recede from the mouth of 
the rivers (by silting) and ipso facto encroach elsewhere; when dry 
predominates in the place the rivers shrink, then the sea returns there 
and ipso facto leaves the other place which it had invaded, dry. 

Aristotle is hampered by the fact that from the nature of the case 
he is really familiar, as his examples show, with one side of the process 
only, the encroaching of land on sea. 


way a nation must be supposed to lose account of the time 
when it first settled in a land that was changing from 

25 a marshy and watery state and becoming dry. Here, too, 
the change is gradual and lasts a long time and men do not 
remember who came first, or when, or what the land was 
like when they came. This has been the case with Egypt. 
Here it is obvious that the land is continually getting drier 
and that the whole country is a deposit of the river Nile. 

30 But because the neighbouring peoples settled in the land 
gradually as the marshes dried, the lapse of time has hidden 
the beginning of the process. However, 1 all the mouths of 
the Nile, with the single exception of that at Canopus, are 
obviously artificial and not natural. And Egypt was 

35 nothing more than what is called Thebes, as Homer, too, 
shows, modern though he is in relation to such changes. 
352 a For Thebes is the place that he mentions ; which implies 
that Memphis did not yet exist, or at any rate was not as 
important as it is now. That this should be so is natural, 
since the lower land came to be inhabited later than that 
which lay higher. For the parts that lie nearer to the 
place where the river is depositing the silt are necessarily 
marshy for a longer time since the water always lies most 

5 in the newly formed land. But in time this land changes 
its character, and in its turn enjoys a period of prosperity. 
For these places dry up and come to be in good condition 
while the places that were formerly well-tempered some 
day 2 grow excessively dry and deteriorate. This happened 
to the land of Argos and Mycenae in Greece. In the time 

10 of the Trojan wars the Argive land was marshy and could 
only support a small population, whereas the land of 
Mycenae was in good condition (and for this reason Mycenae 
was the superior). But now the opposite is the case, for 
the reason we have mentioned : the land of Mycenae has 
become completely dry and barren, while the Argive land 
that was formerly barren owing to the water has now 
become fruitful. Now the same process that has taken 

1 i. e. though there is no record of the beginning of this process the 
facts alleged prove the thesis. 

2 Read TTOTC in 1. 8 with EJFjHN. 

BOOK I. 14 35 2 

place in this small district must be supposed to be going on 15 
over whole countries and on a large scale. 

Men whose outlook is narrow suppose the cause of such 
events to be change in the universe, in the sense of 
a coming to be of the world as a whole. 1 Hence they say 
that the sea is being dried up and is growing less, because 20 
this is observed to have happened in more places now than 
formerly. But this is only partially true. It is true that 
many places are now dry, that formerly were covered with 
water. But the opposite is true too : for if they look they 
will find that there are many places where the sea has 
invaded the land. But we must not suppose that the cause 25 
of this is that the world is in process of becoming. For it 
is absurd to make the universe to be in process because of 
small and trifling changes, when the bulk and size of the 
earth are surely as nothing in comparison with the whole 
world. Rather we must take the cause of all these changes 
to be that, just as winter occurs in the seasons of the year, 
so in determined periods there comes a great winter of 3 
a great year and with it excess of rain. But this excess 
does not ahvays occur in the same place. The deluge in 
the time of Deucalion, for instance, took place chiefly in the 
Greek world and in it especially about ancient Hellas, the 35 
country about Dodona and the Achclous, a river which has 
often changed its course. Here the Selli dwelt and those 
who were formerly called Graeci and now Hellenes. When, 
therefore, such an excess of rain occurs we must suppose 
that it suffices for a long time. We have seen that some 2 
say that the size of the subterranean cavities is what makes 5 
some rivers perennial and others not, whereas we maintain 
that the size of the mountains is the cause, and their density 
and coldness ; for great, dense, and cold mountains catch 
and keep and create most water : whereas if the mountains 
that overhang the sources of rivers are small or porous and 10 
stony and clayey, these rivers run dry earlier. We must 
recognize the same kind of thing in this case too. 
Where such abundance of rain falls in the great winter 

1 Cp. De Caclo, 2;9 b 12; cp. 352^ 16, 353 b 10, 356 10. 

2 349 b 3- 


it tends to make the moisture of those places almost ever 
lasting. 1 But as time goes on places of the latter type 
dry up - more, while those of the former, moist type, 

15 do so less : until at last the beginning of the same cycle 

Since there is necessarily some change in the whole world, 
but not in the way of coming into existence or perishing (for 
the universe is permanent), it must be, as we say, that the 
same places are not for ever moist through the presence of 
sea and rivers, nor for ever dry. And the facts prove this. 

20 The whole land of the Egyptians, whom we take to be the 
most ancient of men, has evidently gradually come into 
existence and been produced by the river. This is clear 
from an observation of the country, and the facts about the 
Red Sea suffice to prove it too. One of their kings tried 

25 to make a canal to it (for it would have been of no little 
advantage to them for the whole region to have become 
navigable; Sesostris is said to have been the first of the 
ancient kings to try), but he found that the sea was higher 
than the land. So he first, and Darius afterwards, stopped 
making the canal, lest the sea should mix with the river 

30 water and spoil it. So it is clear that all this part was once 
unbroken sea. For the same reason Libya the country of 
Ammon is, strangely enough, lower and hollower than the 
land to the seaward of it. For it is clear that a barrier of silt 

35 was formed and after it lakes and dry land, but in course of 
time the water that was left behind in the lakes dried up and 
353 a is now all gone. Again the silting up of the lake Maeotis by 
the rivers has advanced so much that the limit to the size of 
the ships which can now sail into it to trade is much lower 
than it was sixty years ago. Hence it is easy to infer that 

1 Read oifaBai Set (1. 11) with cod. Par. suppl. 314 and Bag., and 
punctuate with olroi . . . TTOIOVVIV in a parenthesis and commas after 
TToiovaiv and TTpocnroXfLneiv. Also in 1. 13 omit /zuXXoi/, probably 
introduced from the next sentence (Par. 2032 and Ol. (lemma) have TM 
7ror/ja>*> without /zdXXoj/). 

2 Omit yiyvfujieva. in 1. 14 with Ideler (Alexander seems not to have 
read it) and read eXarroj/ (so probably Al.). The version given follows 
Vicomercato in making rnvra and 6urfpa refer to oo-ot? 5e and OVTOI y<ip, 
respectively. But text and interpretation of the whole passage are 

BOOK I. 14 353 a 

it, too, like most lakes, was originally produced by the rivers 5 
and that it must end by drying up entirely. 

Again, this process of silting up causes a continuous 
current through the Bosporus l ; and in this case we can 
directly observe the nature of the process. Whenever 
the current from the Asiatic shore threw up a sandbank, 
there first formed a small lake behind it. Later it dried up 10 
and a second sandbank formed in front of the first and 
a second lake. This process went on uniformly and without 
interruption. Now when this has been repeated often 
enough, in the course of time the strait must become like 
a river, and in the end the river itself must dry up. 

So it is clear, since there will be no end 2 to time and the 15 
world is eternal, that neither the Tanais nor the Nile has 
always been flowing, but that the region whence they flow 
was once dry : for their effect may be fulfilled, but time 
cannot. And this will be equally true of all other rivers. 
But if rivers come into existence and perish and the same 20 
parts of the earth were not always moist, the sea must 
needs change correspondingly. And if the sea is always 
advancing in one place and receding in another it is clear 
that the same parts of the whole earth are not always either 
sea or land, but that all this changes in course of time. 

So we have explained that the same parts of the earth are 25 
not always land or sea and why that is so : and also why 
some rivers are perennial and others not. 


I LET us explain the nature of the sea and the reason why 
such a large mass of water is salt and the way in which it 
originally came to be. 

The old writers who invented theogonies say that the 
sea has springs, 3 for they want earth and sea to have 35 
foundations and roots of their own. Presumably they 353* 

1 The Cimmerian and not the Thracian Bosporus is meant : cp. 
Reclus Noui . Gtog. U?rii ersel/e, v, p. 788 sqq. 

2 Read vnoXetytt in 1. 15 with JFHN Al. Ol. (lemma). 
8 e.g. Hesiod., Theog. 282. 


thought that this view was grander and more impressive as 
implying that our earth was an important part of the 
universe. For they believed that the whole world had 
been built up round our earth and for its sake, and that 
the earth was the most important and primary part of it. 
5 Others, 1 wiser in human knowledge, give an account of its 
origin. At first, they say, the earth was surrounded by 
moisture. Then the sun began to dry it up, part of it 
evaporated and is the cause of winds and the turnings back 
of the sun and the moon, 2 while the remainder forms the 

10 sea. So the sea is being dried up and is growing less, and 
will end by being some day entirely dried up. 3 Others l 
say that the sea is a kind of sweat exuded by the earth 
when the sun heats it, and that this explains its saltness 
for all sweat is salt. Others 5 say that the saltness is due 
to the earth. Just as water strained through ashes becomes 

15 salt, so the sea owes its saltness to the admixture of earth 
with similar properties. 

We must now consider the facts which prove that the 
sea cannot possibly have springs. The waters we find on 
the earth either flow or are stationary. All flowing water 

20 has springs. (By a spring, as we have explained above, 6 
we must not understand a source from which waters are 
ladled as it were from a vessel, but a first point at which 
the water which is continually forming and percolating 
gathers. 7 ) Stationary water is either that which has 

1 Alexander refers this to Anaximander (Diels, 2. 27) and Diogenes 
of Apollonia (Diels, 51 A. 9, 17); but it would fit almost any of the 
Milesians , e.g. Thales(cp. Burnet, 9) ; Anaximenes(Diels,3 A. 7, 5). 

2 Cp. 354 b 33sqq. The turnings back were explained as due to 
the resistance of compressed air by Anaximenes (Diels, 3 A. 15) and 
Anaxagoras (Diels, 46 A. 42, 9) ; as due to a lack of the moisture 
that nourished them, according to Alexander (on the authority of 
Theophr.j on 354 b 33 sq. below, by Anaximander and Diogenes. Zeller 
I 5 , p. 223, n. 3, and Heath, Aristarchus, p. 33, refuse to attribute the 
view to Anaximander and interpret rpoTnu as revolutions . 

a cp. 352*19- 

4 Empedocles, cp. 357*24. Diels, 21 B. 55, A. 25 and 66, cp. 
55 A. 99* (Democritus) and 80 B. 32 (Antiphon). 

5 Cp. Diels, 1 1 A. 33 (Xenophanes) ; 57 A. 19 (Metrodorus of Chios) ; 
46 A. 90 (Anaxagoras). 6 349 b 27. 

7 Read Taptevopfvav in 1. 21 with E 2 and Cod. Par. Suppl. 314, els 
rjv in 1. 22 with EjH and Alexander, and inravra with EjHN and 

BOOK II. i 353 b 

collected and has been left standing, marshy pools, for 
instance, and lakes, which differ merely in size, or else it 
comes from springs. In this case it is always artificial, 25 
I mean as in the case of wells, otherwise the spring would 
have to be above the outlet. Hence the water from 
fountains and rivers flows of itself, whereas wells need to 
be worked artificially. All the waters that exist belong to 
one or other of these classes. 

On the basis of this division we can see that the sea 30 
cannot have springs. For it falls under neither of the two 
classes ; it does not flow and it is not artificial ; whereas 
all water from springs must belong to one or other of them. 
Natural standing water from springs is never found on such 
a large scale. 

1 Again, there are several seas that have no communication 35 
with one another at all. The Red Sea, 2 for instance, com- 354 a 
municates but slightly with the ocean outside the straits a , 
and the Hyrcanian 4 and Caspian seas are distinct from this 
ocean and people dwell all round them. Hence, if these 
seas had had any springs anywhere they must have been 

It is true that in straits, where the land on either side 5 
contracts an open sea into a small space, the sea appears 
to flow. But this is because it is swinging to and fro. In 
the open sea this motion is not observed, but where the 
land narrows and contracts the sea the motion that was 10 
imperceptible in the open necessarily strikes the attention. 

The whole of the Mediterranean docs actually flow. 
The direction of this flow is determined by the depth of 
the basins and by the number of rivers. Maeotis flows 

1 Omit eTrfi in 1. 35 with Bon. Ar. St. iii. 

2 i.e. the Indian Ocean, cp. Partsch, Ar. iiber d. Steigen des Nil, 
Abh. d. kon. Sachs. Ges. d. Wiss., 1909, p. 569. 

3 i. e. the Atlantic. 

4 If this is not the Aral, which A. can hardly have known, we must 
explain the plural thus : Hyrcanian is used to denote the Caspian, 
e. g. in Hecataeus ; A. does not seem to have noticed that one and the 
same lake was meant and imagines the Hyrcanian distinct from the 
Caspian by a mere blunder. Or he may have thought of the two as 
different parts of the same sea in the way in which the Aegean and 
Adriatic might be called distinct seas by a writer who knew they were 
one in a sense. Cp. Bolchert, Aristoteles 1 Erdkunde v. Asicn u. 
Libyen, p. 10. 


into Pontus 1 and Pontus into the Aegean. After that the 

15 flow of the remaining seas is not so easy to observe. The 
current of Maeotis and Pontus is due to the number of 
rivers (more rivers flow into the Euxine and Maeotis than 
into the whole Mediterranean with its much larger basin), 
and to their own shallowness. For we find the sea getting 

ao deeper and deeper. Pontus is deeper than Maeotis, the 
Aegean than Pontus, the Sicilian sea than the Aegean; 
the Sardinian and Tyrrhenic being the deepest of all. 
(Outside the pillars of Herakles the sea is shallow owing to 
the mud, but calm, for it lies in a hollow.) 2 We see, then, 
that just as single rivers flow from mountains, so it is 

25 with the earth as a whole : the greatest volume of water 
flows from the higher regions in the north. Their alluvium 
makes the northern seas shallow, while the outer seas are 
deeper. Some further evidence of the height of the 
northern regions of the earth is afforded by the view of 
many of the ancient meteorologists. 3 They believed that 

30 the sun did not pass below the earth, but round its northern 
part, and that it was the height of this which obscured the 
sun and caused night. 

So much to prove that there cannot be sources of the 
sea and to explain its observed flow. 

354 b We must now discuss the origin of the sea, if it has an 
origin, and the cause of its salt and bitter taste. 

What made earlier writers consider the sea to be the 
original and main body of water is this. It seems reasonable 
5 to suppose that to be the case on the analogy of the other 
elements. Each of them has a main bulk which by 
reason of its mass is the origin of that element, 
and any parts which change and mix with the other 
elements come from it. Thus the main body of fire is in 

1 Black Sea. 

2 i. e. it is shallow, yet the water does not flow back (as you might 
expect on the analogy of Maeotis, &c.), because the sea lies in a hollow 
as is proved by the calm (Alexander). This seems the best that can 
be made of this suspicious sentence. The mud is an echo of the 
Sargasso Sea. 

3 e. g. Anaximenes, Diels, 3 A. 7 ( 6), 14. Aristotle is not endorsing 
the view about the sun, and there is no need to condemn this passage 
in consequence as Berger does. 

BOOK II. 2 354 b 

the upper region ; that of air occupies the place next inside 
the region of fire ; while the mass of the earth is that 
round which the rest of the elements are seen to lie. So 10 
we must clearly look for something analogous in the case 
of water. But here we can find no such single mass, as in 
the case of the other elements, except the sea. River water 
is not a unity, nor is it stable, but is seen to be in a con 
tinuous process of becoming from day to day. It was this 15 
difficulty which made people regard the sea as the origin 
and source of moisture and of all water. And so we find 
it maintained that rivers not only flow into the sea but 
originate from it, 1 the salt water becoming sweet by 

But this view involves another difficulty. If this body 
of water is the origin and source of all water, why is it 20 
salt and not sweet ? The reason for this, besides answering 
this question, will ensure our having a right first conception 
of the nature of the sea. 

The earth is surrounded by water, just as that is by the 
sphere of air. and that again by the sphere called that of 
fire (which is the outermost 2 both on the common view 25 
and on ours). Now the sun, moving as it does, sets up 
processes of change and becoming and decay, and by its 
agency the finest and sweetest water is every day carried 
up and is dissolved into vapour and rises to the upper 
region, where it is condensed again by the cold and so 30 
returns to the earth. This, as we have said before/ 5 is the 
regular course of nature. 

Hence all my predecessors 4 who supposed that the sun 
was nourished by moisture are absurdly mistaken. Some 5 
go on to say that the solstices are due to this, the reason 355 a 
being that the same places cannot always supply the sun 
with nourishment and that without it he must perish. For 
the fire we are familiar with lives as long as it is fed, and 5 

1 e.g. Xenophanes, Diels, II B. 30. 

2 Read roimoi/ in 1. 25 with JFHN and Alexander, for TTUVTWV. 

3 1.9. 

4 Cp- 353 b 5- Cp. Burnet, 9 (Thales) ; Diels, 3 A. 7, 5 (Anaxi- 

5 Perhaps Anaximander and Diogenes ; cp. 353 b 6 and 355*22. 


the only food for fire is moisture. 1 As if the moisture 
that is raised could reach the sun ! or this ascent were 
really like that performed by flame as it comes into 
being, and to which they supposed the case of the sun 
to be analogous ! Really there is no similarity. A flame 
is a process of becoming, involving a constant interchange 

10 of moist and dry. It cannot be said to be nourished since 
it scarcely persists as one and the same for a moment. 
This cannot be true of the sun ; for if it were nourished 
like that, as they say it is, we should obviously not only 
have a new sun every day, as Heraclitus 2 says, but a new 

15 sun every moment. Again, when the sun causes the 
moisture to rise, this is like fire heating water. So, as the 
fire is not fed by the water above it, it is absurd to suppose 
that the sun feeds on that moisture, even if its heat made 
all the water in the world evaporate. Again, it is absurd, 
considering the number and size of the stars, that these 

20 thinkers should consider the sun only and overlook the ques 
tion how the rest of the heavenly bodies subsist. Again, 
they are met by the same difficulty as those 3 who say that 
at first the earth itself was moist and the world round the 
earth was warmed by the sun, and so air was generated 
and the whole firmament grew, and the air caused winds 

25 and solstices. The objection is that we always plainly see 
the water that has been carried up coming down again. 
Even if the same amount does not come back in a year or 
in a given country, yet in a certain period all that has been 
carried up is returned. This implies that the celestial 
bodies do not feed on it, and that we cannot distinguish 
between some air which preserves its character once it is 

30 generated and some other which is generated but becomes 

1 Ka\ 8ia TOUT . . . povov (354 b 34~355 a 5) is a parenthesis (Thurot). 

2 Diels, 12 B. 6. 

3 Diels, 51 A. 9 refers this specially to Diogenes. Alexander identifies 
the doctrine with that of 353 b 6 and refers it to Anaximander and 
Diogenes (on the authority of Theophrastus). It seems impossible 
to distinguish the evioi of 354 b 34 and the of Qdo-Koi Tfs here, 355* 22. It 
looks as if the real distinction was that between those who explained 
the * turnings by compressed air and those who explained them by 
lack of nourishment. But in that case Aristotle, Theophrastus, and 
Alexander are all confused and have failed to maintain the distinction. 

BOOK II. 2 355 a 

water again and so perishes ; on the contrary, all the 
moisture alike is dissolved and all of it condensed back 
into water. 

The drinkable, sweet water, then, is light and is all of it 
drawn up: the salt water is heavy and remains behind, but not 
in its natural place. For this is a question which has been 
sufficiently discussed (I mean about the natural place 35 
that water, like the other elements, must in reason have), 
and the answer is this. The place which we see the sea 355 b 
filling is not its natural place but that of water. It seems 
to belong to the sea because the weight of the salt water 5 
makes it remain there, while the sweet, drinkable water 
which is light is carried up. The same thing happens in 
animal bodies. Here, too, the food when it enters the body 
is sweet, yet the residuum and dregs of liquid food are 
found to be bitter and salt. This is because the sweet and 
drinkable part of it has been drawn away by the natural animal 10 
heat and has passed into the flesh and the other parts of 
the body according to their several natures. Now just as 
here it would be wrong for any one to refuse to call the 
belly the place of liquid food because that disappears from 
it soon, and to call it the place of the residuum because 
this is seen to remain, so in the case of our present subject. 
This place, we say, is the place of water. Hence all rivers 15 
and all the water that is generated flow into it : for water 
flows into the deepest place, and the deepest part of the 
earth is filled by the sea. Only all the light and sweet 
part of it is quickly carried off by the sun, while the rest 
remains for the reason we have explained. It is quite 20 
natural that some people should have been puzzled by the 
old question why such a mass of water leaves no trace 
anywhere (for the sea does not increase though innumerable 
and vast rivers are flowing into it every day). But if one 
considers the matter the solution is easy. The same 25 
amount of water does not take as long to dry up when it 
is spread out as when it is gathered in a body, and indeed 
the difference is so great that in the one case it might 
persist the whole day long while in the other it might all 
disappear in a moment as for instance if one were to 


3 o spread out a cup of water over a large table. This is the 
case with the rivers : all the time they are flowing their 
water forms a compact mass, but when it arrives at a vast 
wide place it quickly and imperceptibly evaporates. 

But the theory of the Phaedo 1 about rivers and the sea 

is impossible. There it is said that the earth is pierced 

35 by intercommunicating channels and that the original head 

356* and source of all waters is what is called Tartarus a mass 

of water about the centre, from which all waters, flowing 

and standing, are derived. This primary and original water 

is always surging to and fro, and so it causes the rivers to 

flow on this side of the earth s centre and on that ; for it 

has no fixed seat but is always oscillating about the centre. 

5 Its motion up and down is what fills rivers. Many of these 

form lakes in various places (our sea is an instance of one 

of these), but all of them come round again in a circle to 

the original source of their flow, many at the same point, 

but some at a point opposite to that from which they 

10 issued ; for instance, if they started from the other side of 

the earth s centre, they might return from this side of it. 

They descend only as far as the centre, for after that all 

motion is upwards. Water gets its tastes and colours from 

c-^the kind of earth the rivers happened to flow through. 

But on this theory rivers do not always flow in the same 

15 sense. For since they flow to the centre from which they issue 

forth they will not be flowing down any more than up, but 

in whatever direction the surging of Tartarus inclines to. 

But at this rate we shall get the proverbial rivers flowing 

upwards, 2 which is impossible. Again, where is the water 

that is generated and what goes up again as vapour to come 

20 from ? For this must all of it simply be ignored, 3 since 

the quantity of water is always the same and all the water 

that flows out from the original source flows back to it 

again. This itself is not true, since all rivers are seen to 

end in the sea except where one flows into another. Not 

one of them ends in the earth, but even when one is 

25 swallowed up it comes to the surface again. And those 

1 Phaedo, in c sq. 2 Eur. Med. 410. 

3 Read ft-aipdv in 1. 20. 

BOOK II. 2 356 a 

rivers are large which flow for a long distance through 
a low-lying country, for by their situation and length they 
cut off the course of many others and swallow them up. 1 
This is why the Istrus and the Nile are the greatest of 
the rivers which flow into our sea. Indeed, so many rivers 
fall into them that there is disagreement as to the sources 30 
of them both. 2 All of which is plainly impossible on 
the theory, and the more so as it derives the sea from 

Enough has been said to prove that this is the natural 
place of water and not of the sea, and to explain why sweet 
water is only found in rivers, while salt water is stationary, 35 
and to show that the sea is the end rather than the source 356 b 
of water, analogous to the residual matter of all food, and 
especially liquid food, in animal bodies. 

3 We must now explain why the sea is salt, and ask whether 
it eternally exists as identically the same body, or whether 
it did not exist at all once and some day will exist no 
longer, but will dry up as some people think. 5 

Every one admits this, that if the whole world originated 
the sea did too ; for they make them come into being at 
the same time. It follows that if the universe is eternal 
the same must be true of the sea. Any one who thinks 
like Democritus :5 that the sea is diminishing and will 10 
disappear in the end reminds us of Aesop s tales. His 
story was that Charybdis had twice sucked in the sea : 
the first time she made the mountains visible ; the second 
time the islands ; and when she sucks it in for the last time 
she will dry it up entirely. Such a talc is appropriate 15 
enough to Aesop in a rage with the ferryman, but not to 
serious inquirers. Whatever made the sea remain at first, 
whether it was its weight, as some even of those who hold 
these views say (for it is easy to see the cause here), or 
some other reason clearly the same thing must make it 20 
persist for ever. They must either deny that the water 
raised by the sun will return at all, or, if it does, they 

1 Whereas on the theory these conditions would be unnecessary. 

2 Omit airias in 1. 30 with Alexander and Thurot. 

3 Diels, 55 A. 99** and 100. Cp. 352 a 19. 

D 2 


must admit that the sea persists for ever or as long as 
this process goes on, and again, that for the same period of 
time that sweet water must have been carried up before- 

25 hand. So the sea will never dry up : for before that can 
happen the water that has gone up beforehand will return 
to it : l for if you say that this happens once you must 
admit its recurrence. If you stop the sun s course there is 
no drying agency. If you let it go on it will draw up the 
sweet water as we have said whenever it approaches, and let. 

3 o it descend again when it recedes. This notion about the sea 
is derived from the fact that many places are found to be 
drier now than they once were. Why this is so we have 
explained. 2 The phenomenon is due to temporary excess 
of rain and not to any process of becoming in which 

35 the universe or its parts are involved. Some day the 
357 a opposite will take place and after that the earth will grow 
dry once again. We must recognize that this process 
always goes on thus in a cycle, for that is more satisfactory 
than to suppose a change in the whole world in order 
to explain these facts. But we have dwelt longer on this 
point than it deserves. 

5 To return to the saltness of the sea : those who create 
the sea once for all, or indeed generate it at all, cannot 
account for its saltness. It makes no difference whether 
the sea is the residue of all the moisture that is about the 
earth and has been drawn up by the sun, or whether all 
the flavour existing in the whole mass of sweet water is due 
to the admixture of a certain kind of earth. Since the 

10 total volume of the sea is the same once the water that 
evaporated has returned, it follows that it must either have 
been salt at first too, or, if not at first, then not now either. 
If it was salt from the very beginning, then we want to 
know why that was so ; and why, if salt water was drawn 
up then, that is not the case now. 

Again/Jf it is maintained that an admixture of earth 

15 makes the sea salt (for they say that earth has many 
flavours and is washed down by the rivers and so makes 
the sea salt by its ["admixture), it is strange that rivers 
1 Omitting r^v in 1. 26. 2 I. 14. 

BOOK II. 3 357 a 

should not be salt too. How can the admixture of this 
earth have such a striking effect in a great quantity of 20 
water and not in each river singly ? For the sea, differing 
in nothing from rivers but in being salt, is evidently 
simply the totality of river water, and the rivers are the 
vehicle in which that earth is carried to their common 
destination. 1 

It is equally absurd to suppose that anything has been 
explained by calling the sea the sweat of the earth , like 25 
Empedocles. 2 Metaphors are poetical and so that ex 
pression of his may satisfy the requirements of a poem, but 
as a scientific theory it is unsatisfactory. Even in the case 
of the body it is a question how the sweet liquid drunk be 
comes salt sweat whether it is merely by the departure of 
some element in it which is sweetest, or by the admixture 3 
of something, as when water is strained through ashes. 
Actually the saltness seems to be due to the same cause as 
in the case of the residual liquid that gathers in the bladder. 
That, too, becomes bitter and salt though the liquid we 
drink and that contained in our food is sweet. If then the 357 b 
bitterness is due in these cases (as with the water strained 
through lye) to the presence of a certain sort of stuff that is 
carried along by the urine (as indeed we actually find a salt 
deposit settling in chamber-pots) and is secreted from the 
flesh in sweat (as if the departing moisture were washing 5 
the stuff out of the body), then no doubt the admixture of 
something earthy with the water is what makes the sea 3 

Now in the body stuff of this kind, viz. the sediment of food, 
is due to failure to digest : but how there came to be any 
such thing in the earth requires explanation. Besides, how 10 
can the drying and warming of the earth cause the secretion 
of such a great quantity of water ; especially as that must 
be a mere fragment of what is left in the earth? Again, 
waiving the question of quantity, 4 why does not the earth 

1 And it is therefore absurd that they should not be salt. 

2 Diels, 21 A. 66; B. 55. Cp. 353 b n. 

3 Read KUV in 1. 6. 

4 Read nXdov (with J^FJ and (\arrov in 11. 13, 14 ; 
point of quantity raised in the preceding argument . 


sweat now when it happens to be in process of drying? 1 If 

15 it did so then, it ought to do so now. But it does not : on 
the contrary, when it is dry it grows moist, but when it is 
moist it does not secrete anything at all. How then 2 was 
it possible for the earth at the beginning when it was moist 
to sweat as it grew dry ? Indeed, the theory 3 that main 
tains that most of the moisture departed and was drawn up 

20 by the sun and that what was left over is the sea is more 
reasonable ; but for the earth to sweat when it is moist is 

Since all the attempts to account for the saltness of the; 
sea seem unsuccessful let us explain it by the help of the 
principle we have used already. 4 

25 Since we recognize two kinds of evaporation, one moist, 
the other dry, it is clear that the latter must be recognized 
as the source of phenomena like those we are concerned 

But there is a question which we must discuss first. 
Does the sea always remain numerically one and consisting 
of the same parts, or is it, too, one in form and volume 
while its parts are in continual change, like air and sweet 

30 water and fire ? All of these 5 are in a constant state of 
change, but the form and the quantity of each of them are 
fixed, just as they are in the case of a flowing river or 
a burning flame. The answer is clear, and there is no doubt 
that the same account holds good of all these things alike. 
358 a They differ in that some of them change more rapidly or 
more slowly than others; and 7 they all are involved 
in a process of perishing and becoming which yet affects 
them all in a regular course. 

1 Omit ^ yap ... niKpos in 1. 14 with (apparently) some MSS. of 
Alexander. The point is not that the earth secretes moisture but not 
salt moisture ; but, as the following lines show, that it does not 
secrete anything at all under the conditions supposed. The addition 
may be due to the idea that A. had admitted in the account of rivers 
(i. 13) that the earth did secrete moisture. 

2 Read ovv in 1. 17 with JFHN Al. for d ovv. 

3 Cp. 353^6,356^9. 34i b 6ff. 

del . . . pfvp.a (11. 30-32) is a parenthesis (Bonitz). The apodosis 
begins with (fravepov 1. 32. 

6 Read TO & eldos KCU TO n\^6os in 1. 31 with Bonitz. 

7 Read re for re /cat in 1. I with JFHN. 

BOOK II. 3 358 

This being so we must go on to try to explain why the 
sea is salt. There are many facts which make it clear that 
this taste is due to the admixture of something. First, in 5 
animal bodies what is least digested, the residue of liquid 
food, is salt and bitter, as we said before. All animal 
excreta are undigested, but especially that which gathers in 
the bladder (its extreme lightness proves this ; for every 
thing that is digested is condensed), and also sweat ; in 10 
these then is excreted (along with other matter) an 
identical substance to which this flavour is due. The 
case of things burnt is analogous. What heat fails to 
assimilate becomes the excrementary residue in animal 
bodies, and, in things burnt, ashes. That is why some 
people say that it was burnt earth that made the sea salt. 
To say that it was burnt earth is absurd ; but to say that it 15 
was something like burnt earth is true. We must suppose 
that just as in the cases we have described, so in the world 
as a whole, everything that grows and is naturally generated 
always leaves an undigested residue, like that of things 
burnt, consisting of this sort of earth. All the earthy stuff in 
the dry exhalation l is of this nature, and it is the dry ex- 20 
halation which accounts for its great quantity. Now since, 
as we have said, the moist and the dry evaporations are 
mixed, some quantity of this stuff must always be included 
in the clouds and the water that are formed by condensa 
tion, and must redescend to the earth in rain. This process 25 
must always go on with such regularity as the sublunary 
world admits of, and it is the answer to the question how 
the sea comes to be salt. 

It also explains why rain that comes from the south, and 
the first rains of autumn, are brackish. The south is 
the warmest of winds a and it blows from dry and hot ?,o 
regions. Hence it carries little moist vapour and that is 
why it is hot. (It makes no difference even if this is not 

1 Read uvadv^idad in 1. 20 with Thurot. dvaQvptacrtv is read by all 
the MSS. and by Alexander. The mistake may be due to the failure 
to recognize that the dvadv pitta is may be charged with earthy particles. 

2 Omit KG! T<U pcyeOei KOI ro> Tri/eu/iari (1. 29), which make no sense 
in connexion with dXfeii/oraror. Al. does not seem to have read the 
words. Ol. does, but the yp. " dXrjOivwraTos " which he records suggests 
that the received text was seen to be nonsense. 


its true character and it is originally a cold wind, for it be 
comes warm on its way by incorporating with itself a great 
quantity of dry evaporation from the places it passes over.) 

35 The north wind, on the other hand, coming from moist 
358 b regions, is full of vapour and therefore cold. It is dry in 
our part of the world because it drives the clouds away 
before it, but in the south it is rainy ; just as the south is 
a dry wind in Libya. So the south wind charges the rain 
that falls with a great quantity of this stuff. Autumn l rain 

5 is brackish because the heaviest water must fall first ; so 
that that which contains the greatest quantity of this kind 
of earth descends quickest. 

This, too, is why the sea is warm. Everything that has 
been exposed to fire contains heat potentially, as we see in 
the case of lye and ashes and the dry and liquid excreta of 

10 animals. Indeed those animals which are hottest in the 
belly have the hottest excreta. 

The action of this cause is continually making the sea 
more salt, but some part of its saltness is always being 
drawn up with the sweet water. This is less than the sweet 
water in the same ratio in which the salt and brackish 

15 element in rain is less than the sweet, and so the saltness 
of the sea remains constant on the whole. Salt water when 
it turns into vapour becomes sweet, and the vapour does not 
form salt water when it condenses again. This I know by 
experiment. The same thing is true in every case of the 
kind : wine 2 and all fluids that evaporate and condense 

20 back into a liquid state become water. They all are water 
modified by a certain admixture, the nature of which 
determines their flavour. But this subject must be con 
sidered on another more suitable occasion. 

For the present let us say this. The sea is there and 

2 5 some of it is continually being drawn up and becoming 
sweet ; this returns from above with the rain. But it is now 
different from what it was when it was drawn up, and its 
weight makes it sink below the sweet water. 3 This process 

1 Kai ( b 4) corresponds to re ( a 29) (Thurot). 

2 It is not true of wine. 

BOOK II. 3 358 b 

prevents the sea, as it does rivers, 1 from drying up except 
from local causes (this must happen to sea and rivers alike). 
On the other hand the parts neither of the earth nor of the sea 3 
remain constant but only their whole bulk. For the same 
thing is true of the earth as of the sea : some of it is carried 
up and some comes down with the rain, and both that which 
remains on the surface and that which comes down again 
change 2 their situations. 

There is more evidence to prove that saltness is due to the 
admixture of some substance, besides that which we have 35 
adduced. Make a vessel of wax and put it in the sea, 359 a 
fastening its mouth in such a way as to prevent any water 
getting in. Then the water that percolates through the wax 
sides of the vessel is sweet, the earthy stuff, the admixture 
of which makes the water salt, being separated off as it were 
by a filter. 3 It is this stuff which makes salt water heavy 5 
(it weighs more than freshwater) and thick. The difference 
in consistency is such that ships with the same cargo very 
nearly sink in a river when they are quite fit to navigate in 
the sea. This circumstance has before now caused loss to 10 
shippers freighting their ships in a river. That the thicker 
consistency is due to an admixture of something is proved 
by the fact that if you make strong brine by the admixture 
of salt, eggs, even when they are full, float in it. It almost 
becomes like mud ; such a quantity of earthy matter is there 15 
in the sea. The same thing is done in salting fish. 

Again if, as is fabled, there is a lake in Palestine, such 
that if you bind a man or beast and throw it in it floats and 
does not sink, this would bear out what we have said. They 20 
say that this lake is so bitter and salt that no fish live in it 
and that if you soak clothes in it and shake them it cleans 
them. The following facts all of them support our theory 
that it is some earthy stuff in the water which makes it salt. 
In Chaonia there is a spring of brackish water that flows into 25 
a neighbouring river which is sweet but contains no fish. The 
local story is that when Heracles came from Erytheia driving 

1 CP- 359 b 22. 

2 Read /ifrafriAXfi in 1. 33 with EJFHN 2 . 

3 Cp. Hist. An. viii. 590*24. Diels, 21 A. 66. Facts do not bear 
out this statement ; cp. Uiels, Hermes, xl, p. 310. 


the oxen and gave the inhabitants the choice, they chose salt 

30 in preference to fish. They get the salt from the spring. 
They boil off some of the water and let the rest stand ; when 
it has cooled and the heat and moisture have evaporated 
together it gives them salt, not in lumps but loose and light 
like snow. It is weaker than ordinary salt and added freely 

35 gives a sweet taste, and it is not as white as salt generally 
359 b is. Another instance of this is found in Umbria. There is 
a place there where reeds and rushes grow. They burn 
some of these, put the ashes into water and boil it off. 
When a little water is left and has cooled it gives a quantity 
of salt. 1 

5 Most salt rivers and springs must once have been hot. 
Then the original fire in them was extinguished but the earth 
through which they percolate preserves the character of lye 
or ashes. Springs and rivers with all kinds of flavours are 
found in many places. These flavours must in every case 

10 be due to the fire that is or was 2 in them, for if you expose 
earth to different degrees of heat it assumes various kinds 
and shades of flavour. It becomes full of alum and lye and 
other things of the kind, and the fresh water percolates 
through these and changes its character. Sometimes it be- 

15 comes acid as in Sicania, a part of Sicily. There they get 
a salt and acid water which they use as vinegar to season 
some of their dishes. In the neighbourhood of Lyncus, too, 
there is a spring of acid water, and in Scythia a bitter 
spring. The water from this makes the whole of the river 
into which it flows bitter. 3 These differences are explained 

20 by a knowledge of the particular mixtures that determine 
different savours. 4 But these have been explained in 
another treatise. 5 

We have now given an account of waters and the sea, 

1 Cp. John Boyes, King of the Wa-Kikuyu, p. 108. They (the 
Kikuyu) used to burn large quantities of green papyrus reed, mixing 
the ashes with their food instead of salt. 

2 Read eyyei/o^eV/?i/ in 1. 10 with J Al. 

3 Cp. Herod, iv. 52, 81. 

4 Read SrjXai, nolot in 1. 20 ; omitting 8e after TTOIOI with EJFHNj Al. 
and keeping 8 after eipijrai with E (original reading) JFHN. 

Perhaps De Sensu c. 4 ; though Ol. (and more doubtfully Al.) refers 
to a treatise IT. 

BOOK II. 3 359 b 

why they persist, how they change, what their nature is, 
and have explained most of their natural operations and 25 

4 Let us proceed to the theory of winds. Its basis is 
a distinction we have already made. 1 We recognize two 
kinds of evaporation, one moist, the other dry. The former 
is called vapour : for the other there is no general name but 30 
we must call it a sort of smoke, applying to the whole of it 
a word that is proper to one of its forms. The moist 
cannot exist without the dry nor the dry without the moist : 
whenever we speak of either we mean that it predominates. 
Now 2 when the sun in its circular course approaches, 
it draws up by its heat the moist evaporation : when it 35 
recedes the cold makes the vapour that had been raised con- 36o a 
dense back into water which falls and is distributed through 
the earth. 3 (This explains why there is more rain in winter 
and more by night than by day: though the fact is not 
recognized because rain by night is more apt to escape ob 
servation than by day.) But there is a great quantity of fire 5 
and heat in the earth, and the sun not only draws up the 
moisture that lies on the surface of it, but warms and dries 
the earth itself. Consequently, since there are two kinds of 
evaporation, as we have said, one like vapour, the other like 
smoke,both of them are necessarily generated. Thatinwhich 10 
moisture predominates is the source of rain, as we explained 
before, 4 while the dry evaporation is the source and sub 
stance of all winds. That things must necessarily take this 
course is clear from the resulting phenomena themselves, 5 
for the evaporation that is to produce them must necessarily 15 
differ ; and the sun and the warmth in the earth not only 
can but must produce these evaporations. 

Since the two evaporations are specifically distinct, wind 
and rain obviously differ and their substance is not the same, 
as those say who maintain that one and the same air when 20 
in motion is wind, but when it condenses again is water. 

1 34 i b 6ff. 

2 Punctuate with Bonitz 610 . . . pa\\ov (11. 2-4) in a parenthesis, 
commas after p.ii\\oi> and after y^v (1. 5), and colon after Oeppuiixiiv (I. 8). 

3 Cp. 346 b 2l, 35. 4 i. 9. 6 i.e. rain and wind. 


1 Air, as we have explained in an earlier book, 2 is made up of 
these as constituents. Vapour is moist and cold (for its 
fluidity is due to its moistness, and because it derives from 
water it is naturally cold, like water that has not been 

25 warmed) : whereas the smoky evaporation is hot and dry. 
Hence each contributes a part, and air is moist and hot. 1 
It is absurd that this air that surrounds us should become 
wind when in motion, whatever be the source of its motion 
on the contrary the case of winds is like that of rivers. We 

30 do not call water that flows anyhow a river, even if there is 
a great quantity of it, but only if the flow comes from 
a spring. So too with the winds ; a great quantity of air 
might be moved by the fall of some large object without 
flowing from any source or spring. 3 

The facts bear out our theory. It is because the evapora- 

35 tion takes place uninterruptedly but differs in degree and 

36o b quantity that clouds and winds appear in their natural 

proportion according to the season ; and it is because there 

is now a great excess of the vaporous, now of the dry and 

smoky exhalation, that some years are rainy and wet, others 

5 windy and dry. Sometimes there is much drought or rain, 

and it prevails over a great 4 and continuous stretch of 

country. At other times it is local ; the surrounding 

country often getting seasonable or even excessive rains 

10 while there is drought in a certain part ; or, contrariwise, all 
the surrounding country gets little or even no rain while 
a certain part gets rain in abundance. The reason for 
all this is that while the same affection is generally apt to 
prevail over a considerable district because adjacent places 
(unless there is something special to differentiate them) 

15 stand in the same relation to the sun, yet on occasion the 
dry evaporation will prevail in one part and the moist in 
another, or conversely. Again the reason for this latter is 

1 The connexion of thought would be easier if this passage were 
transposed (as by Thurot), to follow irtjy^v a 33. If the traditional order 
is kept this passage must be treated as a sort of parenthesis. 

2 De Gen. et Corr. ii. 4. 

3 And we should not call it a wind. 

4 Read Kara 7roXX7> wvexv in 1. 6 with E. If either 7roXX/> or awe vn 
must go it should be <rwc X n as a gloss on TroXX^. Al. certainly read 


BOOK II. 4 360* 

that each evaporation goes over to that of the neighbouring 
district : for instance, the dry evaporation circulates in its 
own place while the moist migrates to the next district or 20 
is even driven by winds to some distant place : or else the 
moist evaporation remains and the dry moves away. Just 
as in the case of the body when the stomach is dry the 
lower belly is often in the contrary state, and when it is dry 
the stomach is moist and cold, so it often happens that 25 
the evaporations reciprocally take one another s place and 

Further, after rain wind generally rises in those places 
where the rain fell, 1 and when rain has come on the wind 
ceases. These are necessary effects of the principles we 
have explained. After rain the earth is being dried by its 30 
own heat and that from above and gives off the evaporation 
which we saw to be the material cause of wind. Again, 
suppose this secretion is present and wind prevails ; the 
heat is continually being thrown off, rising to the upper 
region, and so the wind ceases ; then the fall in temperature 35 
makes vapour form and condense into water. 2 Water also 36l a 
forms and cools the dry evaporation when the clouds are 
driven together and the cold concentrated in them. These 
are the causes that make wind cease on the advent of rain, 
and rain fall on the cessation of wind. 

3 The cause of the predominance of winds 4 from the 5 
north and from the south is the same. (Most winds, as 
a matter of fact, are north winds or south winds. 5 ) These 
are the only regions which the sun does not visit : it 
approaches them and recedes from them, but its course is 
always over the west and the east. Hence clouds collect on 
either side, and when the sun approaches it provokes the 10 

1 Read ytviaOai in 1. 28 with JFHN. 

8 Cp. 346 b 26. Thurot would read i/e ^or for vSap in 1. 35. Then 
the next sentence would not give an alternative mode of the formation 
of water but complete the account given in this. Against this is the 
fact that in the account given in 346 b 20 there is no mention of the 
driving together of clouds or of avrnrtpitTTao-is. 

3 The doctrine of the south wind here is irreconcilable with that in 
c. 5 , 362 a 3 1 . Berger, Gesch. der wissensch. Erdk. d. Griechen, 280, n. 2. 

4 Read OTTO re T^S in 1. 5 with JFHN Al. 
6 Cp. 3 63 a 3, 364* s- 


moist evaporation, and when it recedes to the opposite side 
there are storms and rain. So summer and winter are due 
to the sun s motion to and from the solstices, and water 
ascends and falls again for the same reason. 1 Now since 

15 most rain falls in those regions towards which and from 
which the sun turns and these are the north and the south, 
and since most evaporation must take place where there is 
the greatest rainfall, just as green wood gives most smoke, 

20 and since this evaporation is wind, it is natural that the 
most and most important winds should come from these 
quarters. (The winds from the north are called Boreae, 
those from the south Noti. 2 ) 

The course of winds is oblique : for though the evapora 
tion rises straight up from the earth, they blow round it 
because all the surrounding air follows the motion of the 

25 heavens. 3 Hence the question might be asked whether 
winds originate from above or from below. The motion 
comes from above : before 4 we feel the wind blowing the 
air betrays its presence if there are clouds or a mist, for 
their motion shows that the wind has begun to blow before 
it has actually reached us ; and this implies that the source 

30 of winds is above. But since wind is defined as * a quantity 
of dry evaporation from the earth moving round the earth , 
it is clear that while the origin of the motion is from 
above, the matter and the generation of wind come from 
below. The oblique movement of the rising evaporation is 
caused from above : for the motion of the heavens deter 
mines the processes that are at a distance from the earth, 

35 and the motion from below 5 is vertical and every cause is 
more active where it is nearest to the effect 6 ; but in its 
generation and origin wind plainly derives from the earth. 

1 c p . ,346*35. 

2 This sentence informs us of what was assumed to be known in a 6 
above, and is singularly pointless even for a gloss. 

3 But cp. 34o b 33. 

4 Read comma after av<*6ev (1. 27), no stop after nvtiv, omit 8 (J corr. 
Al. Bag.), no stop after eVt S^Xos , av for *ai/, KIVOV^VI] for Kivovp.fvt)v 
(J corr. and perhaps Al.). 

5 There is nothing to answer /*/ in 1. 35. There should be a colon 
at least after fyyvs. 

6 Therefore the* circular motion of winds cannot be attributed to the 
earth or it would begin at its surface and not at a height. 

BOOK II. 4 36i a 

The facts bear out the view that winds are formed by the 36i b 
gradual union of many evaporations just as rivers derive 
their sources from the water that oozes from the earth. 
Every wind is weakest in the spot from which it blows l ; as 
they proceed and leave their source at a distance they 
gather strength. Thus the winter in the north is windless 5 
and calm : that is, in the north itself ; but the breeze that 
blows from there so gently as to escape observation becomes 
a great wind as it passes on. 

We have explained the nature and origin of wind, the 
occurrence of drought and rains, the reason why rain stops 10 
wind and wind rises after rain, the prevalence of north 
and south winds and also why wind moves in the way 
it does. 2 

5 The sun both checks the formation of winds and stimu 
lates it. When the evaporation is small in amount and 15 
faint the sun wastes it and 3 dissipates by its greater heat the 
lesser heat contained in the evaporation. It also dries up 
the earth, the source of the evaporation, before the latter has 
appeared in bulk : just as, when you throw a little fuel into 
a great fire, it is often burnt up before giving off any smoke. 
In these ways the sun checks winds and prevents them 20 
from rising at all : it checks them by wasting the evapora 
tion, and prevents their rising by drying up the earth 
quickly. Hence calm is very apt to prevail about the rising 
of Orion 4 and lasts until the coming of the Etesiac and 
their forerunners . 

Calm is due to two causes. Either cold quenches the 25 
evaporation, for instance a sharp frost : or excessive heat 
wastes it. In the intermediate periods, too, 5 the causes are 
generally either that the evaporation has not had time to 
develop or that it has passed away and there is none as 
yet to replace it. 

1 But cp. 364 5. 

2 i. e. obliquely, round the earth. 

3 Transpose *ai to follow napaiva (11. 16, 17). So perhaps Ol. 
* The morning rising, about July 13. 

5 Delete comma after &pms (1. 28). 


3 o Both the setting l and the rising 2 of Orion are considered 
to be treacherous and stormy, because they take place at 
a change of season (namely of summer or winter; and 
because the size of the constellation makes its rise last over 
many days 3 ) and a state of change is always indefinite and 
therefore liable to disturbance. 

35 The Etesiae blow after the. summer solstice and the rising 

362* of the dog-star 4 : not at the time when the sun is closest nor 

when it is distant ; and they blow by day and cease at 

night. The reason is that when the sun is near it dries up 

the earth before evaporation has taken place, but when it 

has receded a little its heat and the evaporation are present 

5 in the right proportion ; so the ice melts and the earth, dried 

by its own heat and that of the sun, smokes and vapours. 

They abate at night because the cold of the nights checks 

the melting of the ice. What is frozen gives off no evapora- 

10 tion, nor does that which contains no dryness at all : it is 
only where something dry contains moisture that it gives 
off evaporation under the influence of heat. 

The question is sometimes asked : why do the north 
winds which we call the Etesiae blow continuously after the 
summer solstice, when there are no corresponding south 
winds after the winter solstice ? The facts are reasonable 
enough : for the so-called white south winds do blow at 
the corresponding season, though they are not equally con- 

15 tinuous and so escape observation and give rise to this 
inquiry. The reason for this is that the north wind blows 
from the arctic regions which are full of water and snow. 

1 The morning setting, about mid-November. 

2 The morning rising. There is no contradiction between this and 
1. 23 above. Both statements are vague and each may be referred to 
a different time, especially as in a constellation like Orion the date may 
vary according to the star chosen for observation. The time referred 
to in 1. 23 must be earlier than that indicated here. For the latter cp. 
Polyb. i. 37. 

3 This is suspicious. The times meant are the change from early 
summer to late summer (ozrcopa) and from late summer to winter (cp. 
Theoph. De Lap. ix. 55) ; Eudoxus supposed ozrcopa to begin with 
the rise of Sirius (about the end of July). But this is expressed very 
unsymmetrically in Qepovs rj ^ei/itoi/oy. -yiVerm too suggests a gloss ; if 
the clause is kept we must read yiV<r#<u or insert dion before dia TO 
(Ideler s conjecture). 

4 About 28 July. 

BOOK II. 5 362* 

The sun thaws them and so the Etesiae blow : after rather 
than at the summer solstice. (For the greatest heat is 20 
developed not when the sun is nearest to the north, but 
when its heat has been felt for a considerable period and it 
has not yet receded far. The bird winds blow in the 
same way after the winter solstice. They, too, are weak 
Etesiae, but they blow less and later than the Etesiae. 
They begin to blow only on the seventieth day because the 25 
sun is distant and therefore weaker. They do not blow so 
continuously because only things on the surface of the earth 
and offering little resistance evaporate then, the thoroughly 
frozen parts requiring greater heat to melt them. So they 
blow intermittently till the true Etesiae come on again at 
the summer solstice : for from that time onwards the wind 30 
tends to blow continuously.) But the south wind blows 
from the tropic of Cancer and not from the antarctic region. 1 
There are two inhabitable sections of the earth : one near 
our upper, or northern 2 pole, the other near the other or 
southern pole ; and their shape is like that of a tambourine. 35 
If you draw lines from the centre of the earth they cut out 362 b 
a drum-shaped figure. The lines form two cones ; the base 
of the one is the tropic, of the other the ever visible circle, 3 
their vertex is at the centre of the earth. Two other cones 
towards the south pole give corresponding segments of the 
earth. These sections alone are habitable. Beyond the 5 
tropics no one can live : for there the shade would not fall 4 

1 And therefore we cannot expect any south winds to correspond to the 
trade winds. 

2 Contrast De Caelo 285 b 14. 

3 i.e. that of the circumpolar stars. This is relative to latitude and 
so does not serve the purpose of delimiting zones at all well ; though 
no doubt Aristotle meant the ever visible circles of a given place, e.g. 
Athens. Poseidonius criticizes Aristotle accordingly, cp. Strabo ii. 95, 
Berger Geschichte, p. 306, n. I. It would be more consonant with the 
principles on which Aristotle determined the torrid zone if he meant 
here the arctic circle = that determined by a longest day of 24 hours, 
and Ideler supposes that this is the meaning, and the facts about 
the southern hemisphere support this. For Aristotle cannot have 
thought that the base of the corresponding cone there was the ! 
d<j)avr)s Ku/cXoy of any place in his own hemisphere. If this view is 
correct the phrase 8ia iruvrbs (jxivcpus is singularly unfortunate. Cp. 
363 b 32, and Berger, Eratosthenes, 74, n. 4. 

4 The sense required is always fall ; and Ideler would insert cm 
after <>VK in 1. 6. But Aristotle may have written carelessly. 


to the north, whereas the earth is known to be uninhabitable 
before the sun is in the zenith or the shade is thrown to the 
south : and the regions below the Bear l are uninhabitable 
because of the cold. 

I0 [The Crown, too, moves over this region : for it is in the 
zenith when it is on our meridian]. 2 

So we see that the way in which they now describe the 
geography of the earth is ridiculous. They depict the 
inhabited earth as round, but both ascertained facts and 
general considerations show this to be impossible. If we 
reflect we see that the inhabited region is limited in 

15 breadth, while the climate admits of its extending all round 
the earth. For we meet with no excessive heat or cold in 
the direction of its length but only in that of its breadth ; so 
that there is nothing to prevent our travelling round the 
earth unless the extent of the sea presents an obstacle any 
where. The records of journeys by sea and land bear this 

20 out. They make the length far greater than the breadth. 
If we compute these voyages and journeys the distance from 
the Pillars of Heracles to India exceeds that from Aethiopia 
to Maeotis and the northernmost Scythians by a ratio 
of more than 5 to 3, as far as such matters admit of 

25 accurate statement. Yet 3 we know the whole breadth 4 of 
the region we dwell in up to the uninhabited parts : in one 

1 i.e. where the Bear is in the zenith when it is on the meridian. 

2 The Crown is in the zenith on the meridian of Athens, and the Bear 
marks the limit of the circumpolar stars at Athens. Therefore at 
a place where the Bear is in the zenith the Crown will be circumpolar. 
* This region then is the place where the Bear is in the zenith. 

This is taken to be Aristotle s meaning here by Mullenhoff, Deut 
sche Alter tumskundC) i, p. 235 n. : cp. Berger, Geschichte, p. 305. 

Al. and Ol. take the statement to be a proof that we live in the northern 
temperate zone. * The Crown is obviously between the circle of the 
Bear and the summer tropic; it is in the zenith on our meridian, 
therefore we are in the zone between the Bear and the summer tropic. 
Then this region = Greece. 

Both explanations fail to give any point to the remark, which must 
be a learned interpolation. 

3 The connexion of thought is : our inhabitable zone is not round : 
the ascertained width is to the ascertained length as 3 : 5 ; and the 
excess of length over breadth is really greater than that since the 
3 represents the whole breadth, the 5 not all the length . 

4 Read nXdros in 1. 25 with the MSS. 

BOOK II. 5 362 1 

direction no one lives because of the cold, in the other 
because of the heat. 

But it is the sea 1 which divides as it seems the parts 
beyond India from those beyond the Pillars of Heracles 2 
and prevents the earth from being inhabited all round. 

Now since there must be a region bearing the same rela- 30 
tion to the southern pole as the place we live in bears to 
our pole, it will clearly correspond in the ordering of its 
winds as well as in other things. So just as we have 
a north wind here, they must have a corresponding wind 
from the antarctic/ 5 This wind cannot reach us since our own 35 
north wind is like a land breeze 4 and does not even reach 5 
the limits of the region we live in. G The prevalence of 
north winds 7 here is due to our lying near the north. Yet 
even here they give out and fail to penetrate far : in the 5 
southern sea beyond Libya east and west winds are always 
blowing alternately, like north and south winds with us. 8 
So it is clear that the south wind is not the wind that blows 
from the south pole. It is neither that nor the wind from 
the winter tropic. For symmetry would require another 10 
wind blowing from the summer tropic, which there is not, 
since we know that only one wind blows from that quarter. 
So the south wind clearly blows from the torrid region. 
Now the sun is so near to that region that it has no water, 
or snow 10 which might melt and cause Etesiac. But because 15 
that place is far more extensive and open the south wind is 
greater and stronger and warmer than the north and 
penetrates farther to the north than the north wind does to 
the south. 11 

1 And not the climate. 

2 Delete the comma before T&> (1. 29). 

3 Omit u>v in line 34 with E,Nj Al. 

4 i.e. it has a short range. 

6 Omit (o-Ttv in 1. I with E t and supply bu jKti from fivvaroi/ SirjKdv. 

6 Omit tats . . . Trvfl (1. 2) with Ejl^ Nj Al. Whoever put it in missed 
the point of dnoyciov. 

7 Cp. 364* 5, 361* 4. 

8 Punctuate: &?ot . . . TOTTCOV (11. 10-12) a parenthesis: colon after 
HTroSoxm : colon after TOTTCOV (Bonitz). Read o vthos (JFHN) in 1. 8. 

9 i. e. southwards. 

10 Read x^vas (comp. Partsch, p. 586) in 1. 14 and rfgtv (EJ 2 F corr. 
HN), cp. 362 a i8, 364" 8-10. 

11 But cp. 364*5. 

E 2 




The origin of these winds 1 and their relation to one 
20 another has now been explained. 

Let us now explain the position of the winds, 2 their oppo- 6 
sitions, which can blow simultaneously with which, and 
which cannot, their names and number, and any other of 
their affections that have not been treated in the particular 

25 questions . 3 What we say about their position must be 
followed with the help of the figure. For clearness sake 
we have drawn the circle of the horizon, which is round, but 
it represents 4 the zone in which we live 5 ; for that can be 

30 divided in the same 
way. Let us also be 
gin by laying down 
that those things are 
locally contrary which 
arc locally most dis 
tant from one another, 
just as things speci 
fically most remote 
from one another are 
specific contraries. 
Now things that face 
one another from opposite ends of a diameter are locally 
most distant from one another. 

Let A be the point where the sun sets at the equinox and 
B, the point opposite, the place where it rises at the 
b equinox. Let there be another diameter cutting this at 
right angles, and let the point II on it be the north and its 
diametrical opposite the south. Let Z be the rising of 
the sun at the summer solstice and E its setting at the 
5 summer solstice ; A its rising at the winter solstice, and F 
its setting at the winter solstice. Draw a diameter from Z 
to F and from A to E. Then since those things are locally 
contrary which are most distant from one another in space, 
and points diametrically opposite are most distant from one 

1 i. e. north and south winds. 

2 This chapter should be compared with the Vcntontm Situs et 
Cognomina (vol. vi. of this translation). 

* Not in the existing Problems, however. 

4 Read avrov in 1. 28 with FjHN Al. 5 Which is not round. 

BOOK II. 6 363 

another, those winds must necessarily be contrary to one 
another that blow from opposite ends of a diameter. 10 

The names of the winds according to their position are 
these. Zephyrus is the wind that blows from A, this being 
the point where the sun sets at the equinox. Its contrary 
is Apeliotes blowing from B the point where the sun rises 
at the equinox. The wind blowing from II, the north, is 
the true north wind, called Aparctias 1 : while Notus blow- 15 
ing from is its contrary ; for this point is the south and 
is contrary to II, being diametrically opposite to it. 
Caecias blows from Z, where the sun rises at the summer 
solstice. Its contrary is not the wind blowing from E but 
Lips blowing from F For Lips blows from the point 
where the sun sets at the winter solstice and is diametrically 
opposite to Caecias : so it is its contrary. Kurus blows 20 
from A, coming from the point where the sun rises at the 
winter solstice. It borders on Notus, and so we often find 
that people speak of Euro-Noti . Its contrary is not 
Lips blowing from F but the wind that blows from E which 
some call Argestes, some Olympias, and some Sciron. This 25 
blows from the point where the sun sets at the summer 
solstice, and is the only wind that is diametrically opposite 
to Eurus. These are the winds that are diametrically 
opposite to one another and their contraries. 

There are other winds which have no contraries. The 
wind they call Thrascias, which lies between Argestes and 
Aparctias, blows from I ; and the wind called Mcses, which 30 
lies between Caecias and Aparctias, from K. (The line IK 
nearly coincides with the ever visible circle, 2 but not quite.) 
These winds have no contraries. Mcses r: has not, or else 
there would be a wind blowing from the point M which is 
diametrically opposite. Thraskias corresponding to the 
point 1 has not, for then there would be a wind blowing 
from N, the point which is diametrically opposite. (But 
perhaps a local wind which the inhabitants of those parts 
call Phoenicias blows from that point.) 

1 Omit rat after /So^ as- Sc in 1. 14 with KJFHN Al., cp. Capelle, A r ./Z?. 
/. d. klass. Alt., 1905, p. 542, n. I. 

2 Cp. 362 3. Mtillenhoff, 1). A., p. 257 ; Berger, GescJiichte, p. 304. 

3 Omit ovTf OpaarKia in 1. 33 with JFjHjN Al. 


These are the most important and definite winds and 
these their places. 

5 There are more winds from the north than from the 
south. The reason for this is that the region in which we 
live lies nearer to the north. Also, much more water and 
snow is pushed aside into this quarter because the other lies 

TO under the sun and its course. When this thaws and soaks 
into the earth and is exposed to the heat of the sun and the 
earth it necessarily causes evaporation to rise in greater 
quantities and over a greater space. 1 

Of the winds we have described Aparctias is the north 
wind in the strict sense. 2 Thrascias and Meses are north 

5 winds too. (Caecias is half north and half east.) South 
are that which blows from due south and Lips. East, the 
wind from the rising of the sun at the equinox and Eurus. 
Phoenicias is half south and half cast. West, the wind from 
the true west and that called Argestes. More generally 
these winds are classified as northerly or southerly. The 

20 west winds are counted as northerly, for they blow from the 
place of sunset and are therefore colder ; the east winds as 
southerly, for they are warmer because they blow from the 
place of sunrise. So the distinction of cold and hot or warm 
is the basis for the division of the winds into northerly and 
southerly. East winds are warmer than west winds because 

25 the sun shines on the east longer, whereas it leaves the west 
sooner and reaches it later. 3 

Since this is the distribution of the winds it is clear that 
contrary winds cannot blow simultaneously. They are 
diametrically opposite to one another and one of the two 
must be overpowered and cease. Winds that are not 
diametrically opposite to one another may blow simultane- 

3 o ously : for instance the winds from Z and from A. Hence 
it sometimes happens that both of them, though different 
winds and blowing from different quarters, are favourable to 
sailors making for the same point. 

1 C P . 363-3, 13. 

2 Read pco-ys (1. 15) and omit KOIVUS apyeWov (1. 14) with EHN Ol. 

3 A poor argument even for a flat-earth man ; and for Aristotle with 
his round earth lamentable. Perhaps the sentence should be con 

BOOK II. 6 364 

Contrary winds commonly blow at opposite seasons. 
Thus Caecias and in general the winds north of the summer 
solstice blow about the time of the spring equinox, but 
about the autumn equinox Lips ; and Zephyrus about the 
summer solstice, but about the winter solstice Eurus. 

Aparctias, Thrascias, and Argestes are the winds that 
fall on others most and stop them. Their source is so close 5 
to us that they are greater and stronger than other winds. 
They bring fair weather most of all winds for the same 
reason, for, blowing as they do, from close at hand, 1 they 
overpower the other winds and stop them ; they also blow 
away the clouds that are forming and leave a clear sky 
unless they happen to be very cold. Then they do not 10 
bring fair weather, but being colder than they are strong 
they condense the clouds before driving them away. 

Caecias does not bring fair weather because it returns 
upon itself. Hence the saying : Bringing it on himself as 
Caecias does clouds. 

When they cease, winds are succeeded by their neigh 
bours in the direction of the movement of the sun. For an 15 
effect is most apt to be produced in the neighbourhood of 
its cause, and the cause of winds moves with the sun. 

Contrary winds have either the same or contrary effects. 
Thus Lips and Caecias, sometimes called Hellespontias. are 
both rainy. 2 Argestes and Eurus are dry : the latter being 20 
dry at first and rainy afterwards. Meses and Aparctias are 
coldest and bring most snow. Aparctias, Thrascias, and 
Argestes bring hail. Notus, Zephyrus, and Eurus are hot. 
Caecias covers the sky with heavy clouds, Lips with lighter 
ones. Caecias does this because it returns upon itself and 25 
combines the qualities of Boreas and Eurus. By being 
cold it condenses and gathers the vaporous air, and because 

1 But cp. 36i b 3. 

8 Omit Ka\ tvpos, ov aTri)\ia)Ti]v in 1. 19. The clause is introduced by 
olov and should contain illustrations of contrary winds and their effects. 
So the words K<U . . . aTrrjXiuTTjv have no place in it. They may have 
intruded from a marginal note suggested by the next sentence (T(\( VTVV 
8t v8aTu8r]s) or else *ai (vpos is due to the line below and ov OTTT/A. was 
added, perhaps, if due east wind is meant, with the idea of avoiding 
contradiction with the first part of the next sentence. Ol. seems to 
omit the words. F t deletes ov 


it is easterly it carries with it and drives before it a great 
quantity of such matter. Aparctias, Thrascias, and Argestes 
bring fair weather for the reason we have explained before. 1 

30 These winds and Meses are most commonly accompanied by 
lightning. They are cold because they blow 2 from the 
north, and lightning is due to cold, being ejected when the 
clouds contract. 3 Some of these same winds bring hail 
with them for the same reason ; namely, that they cause 
a sudden condensation. 

Hurricanes 4 are commonest in autumn, and next in 
spring : Aparctias, Thrascias, and Argestes give rise to 
them most. This is because hurricanes are generally formed 
when some winds are blowing and others fall on them ; and 
these are the winds which are most apt to fall on others 
5 that are blowing ; the reason for which, too, we have 
explained before. 5 

The Etesiae veer round : they begin from the north, and 
become for dwellers in the west Thrasciae, Argestae, and 
Zephyrus (for Zephyrus belongs to the north 6 ). For 
dwellers in the east they veer round as far as Apeliotes. 

10 So much for the winds, their origin and nature and the 
properties common to them all or peculiar to each. 

We must go on to discuss earthquakes next, for their 7 
cause is akin to our last subject. 

15 The theories that have been put forward up to the present 
date are three, and their authors three men, Anaxagoras of 

1 b 6. 

2 Read (K\6tv in 1. 31 after Thurot, with ed. Camotiana (Yen. 1551), 
and one MS. of Al. 

3 Cp. c. 9. 

4 fKvffpias, a storm-wind bursting from a cloud, has been rendered 
throughout as hurricane . Cp. iii. I, 37o b 3-17 ; though this passage 
agrees more closely with the account of ecnephiae in Theophr. De Sign. 
Temp. ii. 36, 37 (cp. Gilbert, p. 559 sq.) than with iii. i. 

6 Read 6 yap (ecpvpos apKTixus ecmv in 1. 8 with Ideler (E s reading 
with t(pvpos and op/crtKoy transposed) : the Madrid MS. reads 6 yap 
t(pvpos (inapKTias tartf, the Ambrosian MS. o -yap e(pvpos OT\V 6 arrnp- 
KTICIS. Then omit the clause as an interpolation. Bekker s text makes 
no sense, as emerges from Alexander s explanation of it. Ideler s con 
jecture would be a reminiscence of 364* 20 introduced by a confused 
mind as a gloss. 

Omit dpxopevoi . . . TToppco, which seems to have come in from 
Alexander s commentary (113. 27). 

BOOK II. 7 365 

Clazomenac, and before him Anaximenes of Miletus, and 
later Democritus of Abdera. 

Anaxagoras l says that the ether, which naturally moves 
upwards, is caught in hollows below the earth and so shakes 20 
it, for though the earth is really all of it equally porous, its 
surface is clogged up by rain. 2 This implies that part of the 
whole sphere 3 is above and part below : above being 
the part on which we live, below the other. 

This theory is perhaps too primitive to require refutation. 25 
It is absurd to think of up and down otherwise than as 
meaning that heavy bodies move to the earth from every 
quarter, and light ones, such as fire, away from it ; especially 
as we see that, as far as our knowledge of the earth goes, 7,0 
the horizon always changes with a change in our position, 
which proves that the earth is convex and spherical. It is 
absurd, too, to maintain that the earth rests on the air 
because of its size, and then to say that impact upwards 
from below shakes it right through. Besides he gives no 
account of the circumstances attendant on earthquakes : for 
not every country or every season is subject to them. 35- 

Democritus 4 says that the earth is full of water and that 
when a quantity of rain-water is added to this an earthquake 
is the result. The hollows in the earth being unable to ad 
mit the excess of water it forces its way in and so causes an 
earthquake. Or again, the earth as it dries draws the water 
from the fuller to the emptier parts, and the inrush of the 5 
water as it changes its place causes the earthquake. 

Anaximenes 5 says that the earth breaks up when it grows 
wet or dry, and earthquakes are due to the fall of these 
masses as they break away. Hence earthquakes take place 
in times of drought and again of heavy rain, since, as we 1 
have explained, the earth grows dry in time of drought and 
breaks up, whereas the rain makes it sodden and destroys 
its cohesion. 

But if this were the case the earth ought to be found to 
be sinking in many places. Again, why do earthquakes 

1 Cp. Diels, 46 A. i, 9 ; 42, 12 ; 89. 

2 eWi . . . <TOfji<j)r)i> (1. 22) is parenthetical. 

3 For Anaxagoras it is not a sphere. 4 Diels, 55 A. 97, 98. 
5 Diels, 3 A. 7, 8 ; 21 ; 2. 28 (Anaximander). 


frequently occur in places which are not excessively subject 
15 to drought or rain, as they ought to be on the theory ? Be 
sides, on this view, earthquakes ought always to be getting 
fewer, and should come to an end entirely some day: the 
notion of contraction by packing together implies this. So 
20 if this is impossible the theory must be impossible too. 

1 We have already shown 2 that wet and dry must both 8 
give rise to an evaporation : earthquakes are a necessary 
consequence of this fact. The earth is essentially dry, but 

25 rain fills it with moisture. Then the sun and its own fire 
warm it and give rise to a quantity of wind both outside 
and inside it. This wind sometimes flows outwards in 
a single body, sometimes inwards, and sometimes it is 
divided. All these are necessary laws. Next we must find 

30 out what body has the greatest motive force. This will 
certainly be the body that naturally moves farthest and is 
most violent. Now that which has the most rapid motion 
is necessarily the most violent ; for its swiftness gives its 
impact the greatest force. Again, the rarest body, that 
which can most readily pass through every other body, is 

35 that which naturally moves farthest. Wind satisfies these 
366 a conditions in the highest degree 3 (fire only becomes flame 

1 The word plays a large part in this chapter and is difficult 
to render in a way that will make its relations to ar)p, the dry i>a/%u aerir, 
and (ii>fp.ns clear. nvtvp-n generally is equivalent to dry avadvp-iaats ; 
that is, all nixvfjia. is dry (ipudu^u rum, and all dry avaBvplaa-ts is nvfvpa. 
But the word nvtv^n is used by preference when the dry <\va6vp.ia<Tis is 
being regarded as the material cause of wind. Again, mxvpa is closely 
related to nvf^os ; for all nvtp.os is dry avadvpiavis (and therefore 
irvfiipa) in motion. We cannot quite say that all irvcvpa is "w^os ; for 
7rvfvp.a often denotes the dry exhalation before it has assumed that 
definite motion which constitutes it an fivepos. But a -nvt f /ij or 
rrvfi p.aT<i in the plural, or the Trixvpa of a definite one (as distinct 
from 7n>f G/za in general), are used as exact equivalents for an iivtuos or 
<*v(p.oi, or the i ii>ep.os . afjp is properly quite distinct from the other 
three: it is a combination of the dry and the moist exhalations wind 
is not (irjp in motion. But twice in this chapter if the text is sound urjp 
is used as an equivalent for nvfvpa (367* II and 20). 

As we cannot fall back on spiritus for nixvp-a with the later trans 
lators, the word wind has been used throughout this chapter both for 
Trvevpa and for apc/io?, but the passages in which it stands for uvepos have 
been noted. 2 34i b 6. 

3 Omit TO nvvp.a KivrjTiKov in 1. 1 with E, and apparently Al. Remove 
the comma after TOIOVTT) and read a comma instead of a full stop after 
(1. 3)- 

BOOK II. 8 366 a 

and moves rapidly when wind accompanies it) : so that not 
water nor earth is the cause of earthquakes but wind that 
is, the inrush of the external evaporation into the earth. 

Hence, since the evaporation generally follows in a con- 5 
tinuous body in the direction in which it first started, and 
either all of it flows inwards or all outwards, most earth 
quakes and the greatest are accompanied by calm. It is 
true that some take place when a wind is blowing, but this 
presents no difficulty. We sometimes find several winds l 
blowing simultaneously. If one of these enters the earth i 
we get an 2 earthquake attended by wind. Only these 
earthquakes are less severe because their source and cause 
is divided. 

Again, most earthquakes and the severest occur at night 
or, if by day, about noon, that being generally the calmest 
part of the day. For when the sun exerts its full power (as i 
it does about noon) it shuts the evaporation into the earth. 
Night, too, is calmer than day. The absence of the sun 
makes the evaporation return into the earth like a sort of 
ebb tide, corresponding to the outward 3 flow ; especially 
towards dawn, for the winds, as a rule, begin to blow then, 20 
arid if their source changes about like the Euripus and flows 
inwards the quantity of wind in the earth is greater and 
a more violent earthquake results. 

The severest earthquakes take place where the sea is full 25 
of currents or the earth spongy and cavernous : so they 
occur near the Hellespont and in Achaea and Sicily, and 
those parts of Euboea which correspond to our description 
where the sea is supposed to flow in channels below the 
earth. The hot springs, too, near Aedepsus 4 are due to 
a cause of this kind. It is the confined character of these 
places that makes them so liable to earthquakes. A great 30 
and therefore violent wind is developed, which would 
naturally blow away from the earth : but the onrush of the 
sea in a great mass thrusts it back into the earth. The 
countries that are spongy below the surface are exposed to 366 b 
earthquakes because they have room for so much wind. 

1 tivep.01. 2 Omit 6 with E Al. in 1. II. 

3 Read eo> with JFHN Al. in 1. 20. 4 In Euboea. 


For the same reason earthquakes usually take place in 
spring and autumn and in times of wet and of drought be 
cause these are the windiest seasons. Summer with its 
5 heat and winter with its frost cause calm : winter is too 
cold, summer too dry for winds to form. In time of drought 
the air is full of wind ; drought is just the predominance of 
the dry over the moist evaporation. Again, excessive rain 

10 causes more of the evaporation to form in the earth. Then 
this secretion is shut up in a narrow compass and forced into 
a smaller space by the water that fills the cavities. Thiu; 
a great wind l is compressed into a smaller space and so 
gets the upper hand, and then breaks out and beats against 
the earth and shakes it violently. 

15 We must suppose the action of the wind in the earth to 
be analogous to the tremors and throbbings caused in us by 
the force of the wind contained in our bodies. Thus some 
earthquakes are a sort of tremor, others a sort of throbbing. 
Again, we must think of an earthquake as something like 
the tremor that often runs through the body after passing 

20 water as the wind returns inwards from without in one 
volume. 2 

The force wind can have may be gathered not only from 
what happens in the air (where one might suppose that it 
owed its power to produce such effects to its volume), but 

25 also from what is observed in animal bodies. Tetanus and 
spasms are motions of wind, and their force is such that the 
united efforts of many men do not succeed in overcoming 
the movements of the patients. We must suppose, then (to 
compare great things with small), that what happens in the 
earth is just like that. 3 

30 Our theory has been verified by actual observation in 
many places. It has been known to happen that an earth 
quake has continued until the wind 4 that caused it burst 
through the earth into the air and appeared visibly like 

1 (ivffJLOS. 

2 Read ynp ylvtrai for ylvtrai yap with JFj (cp. Thurot s Latin trans 
lation) and begin the parenthesis at 8ta roO. 

3 Read TGIOVTOV 8t] dfl in 1. 29 with JHN for TO avro 8(L Thurot s 
tatin translation also read 6. 

BOOK II. 8 36y a 

a hurricane. 1 This happened lately near Heracleia in 367** 
Pontus and some time past at the island Hiera, one of the 
group called the Aeolian islands. Here a portion of the 
earth swelled up and a lump like a mound rose with a noise : 
finally it burst, and a great wind came out of it and threw up 5 
live cinders and ashes which buried the neighbouring town 
of Lipara and reached some of the towns in Italy. The 
spot where this eruption occurred is still to be seen. 

Indeed, this must be recognized as the cause of the fire 
that is generated in the earth : the air 2 is first broken up in 10 
small particles and then the wind is beaten about and 
so catches fire. 

A phenomenon in these islands affords further evidence 
of the fact that winds move below the surface of the earth. 
When a south wind 3 is going to blow there is a premonitory 
indication : a sound is heard in the places from which the 
eruptions issue. This is because the sea is being pushed on 15 
from a distance and its advance thrusts back into the earth 
the wind that was issuing from it. The reason why there 
is a noise and no earthquake is that the underground spaces 
are so extensive in proportion to the quantity of the air that 
is being driven on 4 that the wind slips away into the void 
beyond. 5 

Again, our theory is supported by the facts that the sun 20 
appears hazy and is darkened in the absence of clouds, and 
that there is sometimes calm and sharp frost before earth 
quakes at sunrise. The sun is necessarily obscured and 
darkened when the evaporation which dissolves and rarefies 
the air begins to withdraw into the earth. The calm, too, 
and the cold towards sunrise and dawn follow from the 25 
theory. The calm we have already explained. There 
must as a rule be calm because the wind flows back into the 
earth : again, it must be most marked before the more 

1 Cp. 37o b 3-17. 

2 acpos is being used very loosely (cp. 1. 20 below) ; this mechanical 
breaking up can hardly stand for the dissolution of the true air into its 



4 df pos again used loosely for dvadvp.ia<ns or -rrvfip-n, cp. 1. II above. 

5 Read vnepxtrai (EHN^ in 1. 19. 


violent earthquakes, for when the wind is not part outside 

30 the earth, part inside, but moves in a single body, its 
strength must be greater. The cold comes because the 
evaporation which is naturally and essentially hot enters 
the earth. (Wind l is not recognized to be hot, because it 
sets the air 2 in motion, and that is full of a quantity of cold 
vapour. It is the same with the breath we blow from our 
mouth : close by it is warm, as it is when we breathe out 
through the mouth, but there is so little of it that it is 
scarcely noticed, whereas at a distance it is cold for the same 
reason as wind. 3 ) Well, when this evaporation disappears 

5 into the earth the vaporous exhalation concentrates * and 
causes cold in any place in which this disappearance 

A sign which sometimes precedes earthquakes can be ex 
plained in the same way. Either by day or a little after 
sunset, in fine weather, a little, light, long-drawn cloud is 

10 seen, like a long very straight line. This is because the 
wind 5 is leaving the air and dying down. Something 
analogous to this happens on the sea-shore. When the sea 
breaks in great waves the marks left on the sand are very 

15 thick and crooked, but when the sea is calm they are slight 
and straight (because the secretion is small)/ As the sea 
is to the shore so the wind is to the cloudy air ; so, when the 
wind drops, this very straight and thin cloud is left, a sort 
of wave-mark in the air. 

20 An earthquake sometimes coincides with an eclipse of the 
moon for the same reason. When the earth is on the point 
of being interposed, but the light and heat of the sun has 
not quite vanished from the air but is dying away, the wind 
which causes the earthquake before the eclipse, turns ofT in- 

25 to the earth, and calm ensues. For there often are winds 7 

ot foe pot. z Here arjp is used in its proper sense. 

01 fivfp.oi. 

Omit di 1 vyporrjra in 1. 5 presumably a gloss and a wrong one: 
moisture is not for Aristotle a cause of concentration of the arpis. 

Which would otherwise disturb it. 

Omit 8iu TO piKpav Troifio-dm TTJV eKKpuriv, which looks like a misguided 
gloss on yaXfjvrj. Vicomercato s conjecture eupvo-tv for e/ocpio-ii> will 
hardly express the breaking of waves on the shore ; for the word 
C P- 35 ia 5- 

BOOK II. 8 36y b 

before eclipses : at nightfall if the eclipse is at midnight, and 
at midnight if the eclipse is at dawn. They are caused by 
the lessening of the warmth from the moon when its sphere 
approaches the point at which l the eclipse is going to take 
place. So the influence which restrained and quieted the 3 o 
air weakens and the air moves again and a wind rises, and 
does so later, the later the eclipse. 2 

A severe earthquake does not stop at once or after 
a single shock, but first the shocks go on, often for about 
forty days ; after that, for one or even two years it gives 
premonitory indications in the same place. The severity of 368* 
the earthquake is determined by the quantity of wind and 
the shape of the passages through which it flows. Where 
it is beaten back and cannot easily find its way out the 
shocks are most violent, and there it must remain in 
a cramped space like water that cannot escape. Any 5 
throbbing in the body does not cease suddenly or quickly, 
but by degrees according as the affection passes off. So 
here the agency which created the evaporation and gave it 
an impulse to motion clearly does not at once exhaust the 
whole of the material from which it forms the wind 3 which 10 
we call an earthquake. So until the rest of this is exhausted 
the shocks must continue, though more gently, and they 
must go on until there is too little of the evaporation left to 
have any perceptible effect on the earth at all. 

Subterranean noises, too, arc due to the wind ; sometimes 
they portend earthquakes but sometimes they have been 15 
heard without any earthquake following. Just as the air 
gives off various sounds when it is struck, so it does when it 
strikes other things ; for striking involves being struck and 
so the two cases are the same. The sound precedes the 
shock because sound is thinner and passes through things 20 
more readily than wind. But when the wind is too weak 
by reason of thinness to cause an earthquake the absence of 
a shock is due to its filtering through readily, though by 
striking hard and hollow masses of different shapes it 

1 Lit. at which, when the moon and its sphere have got there . 

2 Lines 25-32 are almost verbally identical with Probl. 26. 18. 
Read T^J fytairtpov (K\efy(a>s tyiairfpov in 1. 31 with EJ. 


makes various noises, so that the earth sometimes seems to 

35 bellow as the portent-mongers say. 

Water has been known to burst out during an earthquake. 
But that does not make water the cause of the earthquake. 
The wind is the efficient cause whether l it drives the water 
along the surface 2 or up from below : just as winds 3 are the 

30 causes of waves and not waves of winds. 3 Else we might as 
well say that earth was the cause ; for it is upset in an 
earthquake, just like water (for effusion is a form of upset 
ting). No, earth and water are material causes (being 
patients, not agents) : the true cause is the wind. 

The combination of a tidal wave with an earthquake is 

35 due to the presence of contrary winds. It occurs when the 
368 b vvind which is shaking the earth does not entirely succeed 
in driving off the sea which another wind is bringing on, but 
pushes it back and heaps it up in a great mass in one place. 
Given this situation it follows that when this wind gives way 
5 the whole body of the sea, driven on by the other wind, will 
burst out and overwhelm the land. This is what happened 
in Achaea. 4 There 5 a south wind was blowing, but outside 6 
a north wind; then there was a calm and the wind entered 6 
the earth, and then the tidal wave came on and simultaneously 
there was an earthquake. This was the more violent as the 
sea allowed no exit to the wind that had entered the earth, 

10 but shut it in. So in their struggle with one another the 
wind caused the earthquake, and the wave by its settling 
down the inundation. 

Earthquakes are local and often affect a small district only ; 
whereas winds 7 are not local. Such phenomena are local 

15 when the evaporations at a given place are joined by those 
from the next and unite ; this, as we explained, is what 
happens when there is drought or excessive rain locally. 
Now earthquakes do come about in this way but winds 7 do 
not. For earthquakes, rains, and droughts have their source 

1 Read >} for j} in 1. 27 with EFjHN corr. Al. 

2 Cp. 1. 34 sqq. 3 ot tivepot. 
* Cp. 343 b 2. 

5 Transpose eo> and eject (11. 6, 7). The map makes it clear that the 
received text is impossible. 

6 (IVf/JiOS. 7 tit fJLOl. 

BOOK II. 8 368 b 

and origin inside the earth, so that the sun is not equally 
able to direct all the evaporations in one direction. But on 20 
the evaporations in the air the sun has more influence 
so that, when once they have been given an impulse by its 
motion, which is determined by its various positions, they 
flow in one direction. 1 

When the wind is present in sufficient quantity there is 
an earthquake. The shocks are horizontal like a tremor ; 2 
except occasionally, in a few places, where they act vertically, 
upwards from below, like a throbbing. It is the vertical 25 
direction which makes this kind of earthquake so rare. 
The motive force does not easily accumulate in great 
quantity in the position required, since the surface of the 
earth secretes far more of the evaporation than its depths. 
Wherever an earthquake of this kind does occur a quantity 
of stones comes to the surface of the earth (as when you 
throw up things in a winnowing fan), as we see from Sipylus 30 
and the Phlegraean plain and the district in Liguria, which 
were devastated by this kind of earthquake. 

Islands in the middle of the sea are less exposed to earth 
quakes than those near land. First, the volume of the sea 
cools the evaporations and overpowers them by its weight 35 
and so crushes them. Then, currents and not shocks are 369* 
produced in the sea by the action of the winds. Again, it 
is so extensive that evaporations do not collect in it but 
issue from it, 3 and these draw the evaporations from the 
earth after them. 4 Islands near the continent really form 
part of it : the intervening sea is not enough to make 
any difference ; but those in the open sea can only be 5 

1 The general point of this paragraph (s68 b 12-22) is clearly to con 
trast the local nature of earthquakes with the wide range of winds. 
But there is no doubt, as Thurot saw, that the text is corrupt ; though 
the corruption must be old, since Alexander plainly read very much 
the same thing as we do. 

8ia TOITOV roi rponov, 1. 1 8, implies two variants, din TavTrjv TI]V nlrinv 

and TOVTOV TOV npoTTov. One or other of these (presumably the latter) 
should be read, arruo-ny, 1. 19, sc. TCIS avaQvpidfftis. In 1. 20 delete the 
colon and 8 . 

2 Omit \tiv in 1 24 with JFHN ; remove the comma after TOTTOVS-, 
and omit *m after i/<o with JFH Al. 

3 It is difficult to see the point of this. 

4 Therefore the sea cannot be shaken : and the islands cannot be 
shaken without it. 

645-21 \? 


shaken if the whole of the sea that surrounds them is 
shaken too. 

We have now explained earthquakes, their nature and 
cause, and the most important of the circumstances attendant, 
on their appearance. 

10 Let us go on to explain lightning and thunder, and 
further whirlwind, fire-wind, and thunderbolts : for the 
cause of them all is the same. 

As we have said, 1 there are two kinds of exhalation, 
moist and dry, and the atmosphere contains them both 

15 potentially. It, as we have said before,- condenses into 
cloud, and the density of the clouds is highest at their upper 
limit. (For 3 they must be denser and colder on the side 
where the heat escapes to the upper region and leaves them. 
This explains why hurricanes 4 and thunderbolts and all 

30 analogous phenomena move downwards in spite of the fact 
that everything hot has a natural tendency upwards. Just 
as the pips that we squeeze between our fingers are heavy 
but often jump upwards : so these things are necessarily 
squeezed out away from the densest part of the cloud.) 
Now the heat that escapes disperses to the upper region. 

25 But if any of the dry exhalation is caught in the process as 
the air cools, it is squeezed out as the clouds contract and 
collides in its rapid course with the neighbouring r> clouds, 
and the sound of this collision is what we call thunder. 

30 This collision is analogous, to compare small with great, to 
the sound we hear in a flame which men call the laughter or 
the threat of Hephaestus or of Hestia. This occurs when 
the wood dries and cracks and the exhalation rushes on the 

35 flame in a body. So in the clouds, the exhalation is pro- 

369** jected G and its impact on dense clouds causes thunder: the 

variety of the sound is due to the irregularity of the clouds 

1 e.g. 3 4 i l) 6. 

2 e. g. 341 h 36 sqq., 346" 23 sqq. 

3 J . . . m>&> (11. 17-24) is parenthetical; the apodosis begins 17 ntv 
ovv, 1. 24. Read colons after <rv<rTa<nv, 1. 19, and rorror, 1. 25 (Bonitz). 

4 Cp. 37o b 3-i;. 

8 Read rr pi f \ovcri in 1. 28. 

6 Read 17 yiyvopcvr) for yiyrofjievi] 17 in 1. 35 with JFHN Al. 

BOOK II. 9 369 

and the hollows that intervene where their density is inter 
rupted. This, then, is thunder, and this its cause. 

It usually happens that the exhalation that is ejected is 5 
inflamed and burns with a thin and faint fire : this is what 
we call lightning, where we see as it were the exhalation 
coloured in the act of its ejection. 1 It comes into existence 
after the collision and the thunder, though we see it earlier 
because sight is quicker than hearing. The rowing of 
triremes illustrates this : the oars are going back again 10 
before the sound of their striking the water reaches us. 

However, there are some who maintain that there is 
actually fire in the clouds. Empedocles 2 says that it con 
sists of some of the sun s rays which arc intercepted : 
Anaxagoras 3 that it is part of the upper ether (which he 
calls fire) which has descended from above. Lightning, 15 
then, is the gleam of this fire, and thunder the hissing noise 
of its extinction in the cloud. 

But this involves the view that lightning actually is prior 
to thunder and does not merely appear to be so. Again, 
this intercepting of the fire is impossible on either theory, 
but especially when it is said to be drawn down from the 20 
upper ether. Some reason ought to be given why that 
which naturally ascends should descend, and why it should 
not always do so, but only when it is cloudy. When the 
sky is clear there is no lightning : to say that there is, is 
altogether wanton. 

The view that the heat of the sun s rays intercepted in the 25 
clouds is the cause of these phenomena is equally unattrac 
tive : this, too, is a most careless explanation. Thunder, 
lightning, and the rest must have a separate and deter 
minate cause assigned to them on which they ensue. But this 3 
theory does nothing of the sort. It is like supposing that 
water, snow, and hail existed all along and were produced 
when the time came and not generated at all, as if the 
atmosphere brought each to hand out of its stock from time 
to time. They are concretions in the same way as thunder 

1 Perhaps wa-nep should be omitted (there is no trace of it in Al.), 
though it is difficult to account for its presence in the MSS. 

2 Diels, 21 A. 63. 3 Diels, 46 A. I, 9 ; 42, 1 1 ; 84. 

F 2 


35 and lightning are discretions, so that if it is true of either 
that they are not generated but pre-exist, the same must be 
37o a true of the other. 1 Again, how can any distinction be made 
about the intercepting between this case and that of inter 
ception in denser substances such as water ? Water, too, is 
heated by the sun and by fire : yet when it contracts again 
and grows cold and freezes no such ejection as they describe 
5 occurs, though it ought on their theory to take place on a pro 
portionate scale. 2 Boiling is due to the exhalation generated 
by fire: but it is impossible for it to exist in the water 
beforehand ; and besides they call the noise hissing 1 , not 
* boiling . :J But hissing is really boiling on a small scale 4 : 
for when that which is brought into contact with moisture 
and is in process of being extinguished gets the better of it, 
then it boils and makes the noise in question. 

10 Some Cleidemus r> is one of them say that lightning is 
nothing objective but merely an appearance. They com 
pare it to what happens when you strike the sea with a rod 
by night and the water is seen to shine. They say that 
the moisture in the cloud is beaten about in the same way, 
and that lightning is the appearance of brightness that 

15 ensues. 

This theory is due to ignorance of the theory of reflection, 
which is the real cause of that phenomenon. The water 
appears to shine when struck because our sight is reflected 
from r> it to some bright object : hence the phenomenon 

20 occurs mainly by night : the appearance is not seen by day 
because the daylight is too intense and obscures it. 

These are the theories of others about thunder and 
lightning : some maintaining that lightning is a reflection, 
the others that lightning is fire shining through the cloud and 

1 It would therefore have to be true of snow and hail, which it is 
not, if it were true (as this theory implies) of lightning (therefore it is 
not true of lightning). 

2 Read colon for full stop after \eynva-tv (1. 5) : full stop after /i*ye- 
6ovs : rr]v de ^fariv (EFj) TTOKI (Ej). 

3 So they cannot support their view by appealing to the phenomenon 
of boiling. 

4 And therefore (although they speak of hissing and not boiling ) 
the point in the first part of the last sentence does hold against them. 

6 Diels, 49. i. 

6 Read drr avTov in 1. 1 8 with JFN Al. 

BOOK II. 9 37 o 5 

thunder its extinction, the fire not being generated in each 
case but existing beforehand. We say that the same stuff 25 
is wind on the earth, and earthquake under it, and in the 
clouds thunder. The essential constituent of all these 
phenomena is the same : namely, the dry exhalation. If it 
flows in one direction it is wind, in another it causes earth 
quakes ; in the clouds, when they are in a process of change l 
.and contract and condense into water, it is ejected and causes 30 
thunder and lightning and the other phenomena of the 
same nature. 

So much for thunder and lightning. 


1 LET us explain the remaining operations of this secretion 
in the same way as we have treated the rest. When this 
exhalation is secreted 2 in small and scattered quantities and 5 
frequently, and is transitory, and its constitution rare, it 
gives rise to thunder and lightning. But if it is secreted in 
a body and is denser, that is, less rare, we get a hurricane: 5 
The fact that it issues in a body explains its violence : it is 
due to the rapidity of the secretion. Now when this 10 
secretion issues in a great and continuous current the result 
corresponds to what we get when the opposite development 
takes place and rain and a quantity of water are produced. 
As far as the matter from which they are developed goes 4 
both sets of phenomena are the same." As soon as 
a stimulus to the development of either potentiality appears, 
that of which there is the greater quantity present in the 15 
cloud is at once secreted from it, and there results either 
rain, or, if the other exhalation prevails, a hurricane. 

Sometimes the exhalation in the cloud, when it is being 

1 Read /i(T/3aXXouo-t with Thurol in 1. 30. 

2 From the cloud. 

! Cp. 36$ a i , 366 b 33 , 369** 19. 4 The cloud. 

5 Read ravrd in 1. 13 with the Madrid MS. 


secreted, collides with another 1 under circumstances like 
those found when a wind is forced from an open into 
a narrow space in a gateway or a road. It often happens 

20 in such cases that the first part of the moving body is 
deflected because of the resistance due either to the narrow 
ness or to a contrary current, and so the wind forms a circle 
and eddy. It is prevented from advancing in a straight 
line : at the same time it is pushed on from behind ; so it is 
compelled to move sideways in the direction of least resis- 

25 tance. The same thing happens to the next part, and the 
next, and so on, till the series becomes one, that is, till 
a circle is formed : for if a figure is described by a single 
motion that figure must itself be one. 2 This is how eddies 
are generated on the earth, and the case is the same in the 
clouds as far as the beginning of them goes. Only here 
(as in the case of the hurricane which shakes off 3 the cloud 

30 without cessation and becomes a continuous wind) the 
cloud follows the exhalation unbroken, and the exhalation, 
failing to break away from the cloud because of its density, 
first moves in a circle for the reason given and then 
descends, because clouds are always densest on the side 
37l a where the heat escapes. 4 This phenomenon is called 
a whirlwind when it is colourless ; and it is 6 a sort of 
undigested hurricane. There is never a whirlwind when 
the weather is northerly, nor a hurricane when there is 
snow. The reason is that all these phenomena are 

1 Sc. another exhalation in the cloud (Gilbert), and not another cloud 

2 Read cv for KVK\OV in 1. 27 with EHN Al. 

3 Read TOV vtyovs in 1. 29 with H and cod. Par. suppl. 314; cp. Al. 
ad loc. and p. 136. 7, and cp. 371* 10 sq. below. 

The passage is very obscure. The translation assumes (following 
Vicomercato in the main) that the chief point is the contrast of the 
typhoon with the eddy generated on earth (and not as Gilbert thinks 
of the typhoon with the ecnephias) the former descends, the latter 
does not. Incidentally a point of similarity between ecnephias and 
typhoon is alluded to, the continuity of each of them ; and, incidentally 
to that, a point which differentiates typhoon from ecnephias, its shaking 
off the cloud, which is taken up again 37i a 9- But all interpretations 
are unsatisfactory. 

4 Cp. 369 a 16. 

6 Comma after uvepos (1. 2) ; delete commas after nxfruv and u>v. 

Cp. 37O b 8 (KVtQias tivf^os. So Al. 

BOOK III. i 371* 

wind 1 , and wind is a dry and warm evaporation. Now 5 
frost and cold prevail over this principle and quench it 
at its birth : that they do prevail is clear or there could be 
no snow or northerly rain, since these occur when the cold 
does prevail. 

So the whirlwind originates in the failure of an incipient 10 
hurricane to escape from its cloud : it is due to the resis 
tance which generates the eddy, and it consists in the spiral 
which descends to the earth 2 and drags with it the cloud 
which it cannot shake off. It moves things by its wind in 
the direction in which it is blowing in a straight line, and 
whirls round by its circular motion and forcibly snatches up 
whatever it meets. 

When the cloud burns as it is drawn downwards, 15 
that is, when the exhalation becomes rarer, it is called 
a fire-wind, for its fire colours the neighbouring air and 
inflames it. 

When there is a great quantity of exhalation and it is 
rare and is squeezed out in the cloud itself 3 we get a thunder 
bolt. If the exhalation is exceedingly rare this rareness 20 
prevents the thunderbolt from scorching and the poets call 
it bright : if the rareness is less it does scorch and they 
calllt smoky . The former moves rapidly 4 because of its 
rareness, and because of its rapidity passes through an 
object before setting fire to it or dwelling on it so as to 
blacken it : the slower one does blacken the object, but 
passes through it before it can actually burn it. 5 Further, 

1 Read TrveO/za in 1. 4 with J Al. ; cp. 371*29, and 372 :l l8 Travra yap 

a Read eVt yijv in 1. 11 with E 2 JFA1. (Ol. eVl rf)v yfjv lemma and 

3 i. e. in contrast to KaTaanufjifvov in the account of the prester above. 

4 Some complement to (pfpcrai (1. 22) such as Sia rdxovs must be 
supplied (Thurot). 

This division of Kfpavvoi is obscure, perhaps because Aristotle is 
mainly concerned with their being, or being due to, Tri/ft /ia (371*29) 
and less with a systematic classification of them. This may explain 
the fact that the contrast in this sentence is not what we expect ; 
and that the next sentence seems to contradict this. But it may 
be that the next sentence is not intended as a continuation of the 
division begun in this, but is an independent observation confirming 
the pneumatic nature of thunderbolts, which Aristotle inserted without 
noticing that it involved him in at least a verbal contradiction. Or it 


25 resisting substances are affected, unresisting ones are not. 
For instance, it has happened that the bronze of a shield 
has been melted while the woodwork remained intact 
because its texture was so loose that the exhalation filtered 
through without affecting it. 1 So it has passed through 
clothes, too, without burning them, 2 and has merely reduced 
them to shreds. 

Such evidence is enough by itself to show that the 

30 exhalation 3 is at work in all these cases, but we sometimes 
get direct ocular evidence as well, as in the case of the 
conflagration of the temple at Ephesus 4 which we lately 
witnessed. 5 There independent sheets of flame left the 
main fire and were carried bodily in many directions. Now 
that smoke is exhalation and that smoke burns is certain, 
37i b and has been stated in another place before 6 ; but when the 
flame moves bodily, then we have ocular proof that smoke 
is exhalation. On this occasion what is seen in small fires 
appeared on a much larger scale because of the quantity of 
matter that was burning. The beams which were the source 

5 of the exhalation split, and a quantity of it rushed in a body 
from the place from which it issued forth and went up in 
a blaze : so that the flame was actually seen moving through 
the air away and falling on the houses. For 7 we must 
recognize that exhalation accompanies and precedes thunder 
bolts though it is colourless and so invisible. Hence, where 

10 the thunderbolt is going to strike, the object moves before 
it is struck, showing that the exhalation leads the way and 
falls on the object first. Thunder, 8 too, splits things not by 
its noise but because the exhalation that strikes the object 
and that which makes the noise are ejected simultaneously. 

may be supposed that our text is considerably corrupt and that some 
thing essential has been lost. 

1 Colon after dujBrjOtv in 1. 27 and no stop after 6ieX#oi> (Thurot). 

2 Read ^avatv (EHN Al.) in 1. 28. 

3 Read nvtv^a in 1. 29 with J Al. ; cp. a 4. 

4 The date is said to be 356 B.C. This passage need not neces 
sarily be taken to imply that Aristotle was himself an eyewitness 
of the event. 

8 Read c6(u>(iovfji(v in 1. 31 for o-wtfiatvc with EHN. 

6 Cp. 34i b 2i, 388 a 2, De Gen. et Corr. 33^25. 

7 i. e. this is natural, for ... 

8 Omit /cat dffTpanai in 1. II with JFI^N Al. Ol, 

BOOK III. i 37i b 

This exhalation splits the thing it strikes but does not 
scorch it at all. 

We have now explained thunder and lightning and 
hurricane, and further fire-winds, whirlwinds, and thunder- 15 
bolts, and shown that they are all of them forms of the 
same thing and wherein they all l differ. 

2 Let us now explain the nature and cause of halo, rainbow, 
mock suns, and rods, since the same account applies to 20 
them all. 

We must first describe the phenomena and the circum 
stances in which each of them occurs. The halo often 
appears as a complete circle : it is seen round the sun and 
the moon and bright stars, by night as well as by day, and 
at midday or in the afternoon, more rarely about sunrise or 25 

The rainbow never forms a full circle, nor any segment 
greater than a semicircle. At sunset and sunrise the circle 
is smallest and the segment largest : as the sun rises higher 
the circle is larger and the segment smaller. 2 After the 30 
autumn :i equinox in the shorter days it is seen at every 
hour of the day, in the summer not about midday. There 
are never more than two rainbows at one time. 4 Each of 
them is three-coloured ; the colours are the same in both 372* 
and their number is the same, but in the outer rainbow 
they are fainter and their position is reversed. In the inner 
rainbow the first and largest band is red ; in the outer 
rainbow the band that is nearest to this one and smallest 
is of the same colour : the other bands correspond on the 
same principle. These are almost the only colours which 5 
painters cannot manufacture : for there are colours which 
they create by mixing, but no mixing will give red, green, 
or purple. These are the colours of the rainbow, though 
between the red and the green an orange colour is often 

1 Read TTUVTUV avrwv in 1. 17 with EJF. 

2 Really the size of the circle is always the same. 

3 Read neronoipivTjv for uTTtopivijv in 1. 30 with F Al. (fj.(T(&rropii>Tjv J). 

4 Secondary rainbows have under experimental conditions been 
observed to the number of eighteen (Daniell, Text-book of the 
Principles of Physics, p. 479). 


10 Mock suns and rods are always seen by the side of the 
sun, 1 not above or below it nor in the opposite quarter of 
the sky. 2 They are not seen at night but always in the 
neighbourhood of the sun, either as it is rising or setting 
but more commonly towards sunset. They have scarcely 
ever appeared when the sun was on the meridian, though 

15 this once happened in Bosporus where two mock suns rose 
with the sun and followed it all through the day till 

These are the facts about each of these phenomena : the 
cause of them all is the same, for they are all reflections. 
But they are different varieties, and are distinguished by 

20 the surface from which and the way in which the reflection 
to the sun or some other bright object takes place. 

The rainbow is seen by day, and it was formerly thought 
that it never appeared by night as a moon rainbow. This 
opinion was due to the rarity of the occurrence : it was not 
observed, for though it does happen it does so rarely. The 
reason is that the colours are not so easy to see in the dark 

25 and that many other conditions must coincide, and all that 
in a single day in the month. For if there is to be one it 
must be at full moon, 3 and then as the moon is either rising 
or setting. So we have only met with two instances of 
a moon rainbow in more than fifty years. 

We must accept from the theory of optics 4 the fact that 

30 sight is reflected from air and any object with a smooth 
surface just as it is from water ; also that in some mirrors 
the forms of things are reflected, in others only their 
372 b colours. Of the latter kind are those mirrors which are 
so small as to be indivisible for sense. It is impossible 
that the figure of a thing should be reflected in them, for if 
it is.the mirror will be sensibly divisible since divisibility is 
involved in the notion of figure. But since something must 

5 be reflected in them and figure cannot be, it remains that 
colour alone should be reflected. 5 The colour of a bright 

1 i. e. east or west of it. 2 Cp. 377** 27 sqq. 

3 Or nearly so. Scott, Elementary Meteorology, 202. 

4 Alexander observes that the language in which Aristotle speaks of 
vision in this book is not that of his theory in the De Anima. 

5 Cp.373 a 19-23, b 24. 

BOOK III. 2 37 2 b 

object sometimes appears bright in the reflection, but it 
sometimes, either owing to the admixture of the colour of 
the mirror or to weakness of sight, gives rise to the appear 
ance of another colour. 

However, we must accept the account we have given of 
these things in the theory of sensation, 1 and take some 10 
things for granted while we explain others. 

3 Let us begin by explaining the shape of the halo ; why 
it is a circle and why it appears round the sun or the moon 
or one of the other stars : the explanation being in all these 
cases the same. 

Sight is reflected in this way when air and vapour are 15 
condensed into a cloud and the condensed matter is uniform 
and consists of small parts. Hence in itself it is a sign of 
rain, but if it fades away, of fine weather, if it is broken up, 
of wind. For if it does not fade away and is not broken 20 
up but is allowed to attain its normal state, it is naturally 
a sign of rain since it shows that a process of condensation 
is proceeding which must, when it is carried to an end, 
result in rain. For the same reason these haloes are the 
darkest. It is a sign of wind when it is broken up because 25 
its breaking up is due to a wind which exists there but has 
not reached us. This view finds support in the fact that 
the wind blows from the quarter in which the main division 
appears in the halo. Its fading away is a sign of fine 
weather because if the air is not yet 2 in a state to get the 30 
better of the heat it contains and proceed to condense into 
water, this shows that the moist vapour has not yet separated 
from the dry and firelike exhalation : and this is the cause 
of fine weather. 

So much for the atmospheric conditions under which the 
reflection takes place. The reflection is from the mist that 373* 
forms round the sun or the moon, and that is why the halo 
is not seen opposite the sun like the rainbow. Since the 
reflection takes place in the same way from every point 
the result is necessarily a circle or a segment of a circle : 

1 Perhaps De Sensu, c. 3. 

2 Read 7ro> in 1. 30. 

373 a 


for if the lines start from the same point and end 
at the same point and are equal, 1 the points where they 

5 form an angle will always lie on a circle. 

Let AFB and AZB and AAB be lines each of which goes 
from the point A to the point B and forms an angle. Let 
the lines AF, AZ, AA be equal and those at B, FB, ZB, AB 
equal too. Draw the line AEB. Then the triangles are 

10 equal ; for their base AEB is equal. 
Draw perpendiculars to AEB from the 
angles; FE from F, ZE from Z, AE 
from A. Then these perpendiculars are 
equal, being in equal triangles. 2 And 
they are all in one plane, being all at 

15 right angles to AEB and meeting at a 
single point E. So if you draw the line 3 
it will be a circle and E its centre. Now 
B is 4 the sun, A the eye, and the circum 
ference passing through the points FZA 
the cloud from which the line of sight 
is reflected to the sun. 

The mirrors must be thought of as contiguous : each of 

20 them is too small to be visible, but their contiguity makes 
the whole made up of them all to seem one. The bright 
band is the sun, which is seen as a circle, appearing 
successively in each of the mirrors as a point indivisible to 
sense. 5 The band of cloud next to it is black, its colour 

2 5 being intensified by contrast with the brightness of the 
halo. The halo is formed rather near 7 the earth because 

1 This begs the question and stultifies the succeeding demonstration, 
cp. Poske, Zschr. f. Math. u. Phys., 1883, p. 134544.; Gilbert, 
p. 602 sqq. 

2 Colon after rpiyuvots (1. 14). 

3 Through TZA. 

4 Read TTI (EJFHNj) for eVrw in 1. 16. 

: Cp. 372* 32 sqq. and note ; 373 b 24 sqq. 

5 Transposing npbs fie rfj yfj . . . (pavfpov (11. 23-5) after irapa 8e 
TOVTO . . . p.(\avTpa with Vicomercato and others. Better, perhaps, 
put these clauses after dtpos (1. 29) : yiyvovrai (at Xw) will then be the 
verb to npbs df rfjy^ for which it is difficult to supply a suitable verb in 
the place in which Vicomercato s transposition leaves it. 

7 Or nearer, i.e., than the rainbow, cp. 374* I. 

BOOK III. 3 373 a 

that is calmer l : for where there is wind it is clear that no 
halo can maintain its position. 2 

Haloes are commoner round the moon because the greater 
heat of the sun dissolves the condensations of the air more 

Haloes are formed round stars for the same reasons, but 30 
they are not prognostic in the same way because the 
condensation they imply is so insignificant as to be 

4 We have already stated that the rainbow is a reflection : 
we have now to explain what sort of reflection it is. to 
describe its various concomitants, and to assign their causes. 

Sight is reflected from all smooth surfaces, such as are 35 
air and water among others. Air must be condensed if it 373 b 
is to act as a mirror, though it often gives a reflection even 
uncondensed when the sight is weak. Such was the case of 
a man whose sight was faint and indistinct. He always 5 
saw an image in front of him and facing him as he walked. 
This was because his sight was reflected back to him. Its 
morbid condition made it so weak and delicate that the air 
close by acted as a mirror, just as distant and condensed air 
normally does, and his sight could not push it back. 3 So 4 10 
promontories in the sea loom 5 when there is a south-east 
wind, and everything seems bigger, and in a mist, too, 

1 Cp. 34O b 33. It is difficult to be certain what part of the atmosphere 
Aristotle has in mind here : his account of the various strata is obscure. 
It must be inside the tops of the highest mountains, for above them 
there are no clouds ; and outside the innermost stratum which is 
dominated by the rays of the sun reflected from the earth s surface, 
and where there are also no clouds. Vicomercato thinks that we 
must suppose a specially windy stratum just below the tops of the 
highest mountains ; our calm stratum would be between that and 
the innermost stratum. But it may be (in spite of his objections) that 
the whole stratum between the innermost and the tops of the highest 
mountains is meant, and that it is contrasted with the higher strata 
which are involved in perpetual flow by the jci>K\o</>opta. In this case 
nvev^n would be used rather loosely of that flow. 

* (But they do). 

3 Read a dash after dnwBdv (1. 9). 

4 The connexion seems to be that the state of the air conditions 
what is seen. Ideler thinks there is a lacuna before this sentence, or 
else that the sentence itself is spurious. 

5 * Distant objects are said to loom when they appear abnormally 
elevated above their true positions. Scott, El. Mef., p. 207. 


things seem bigger : so, too, the sun and the stars seem 
bigger when rising and setting than on the meridian. But 
things are best reflected from water, and even in process of 

15 formation it is a better mirror than air, for each of the 
particles, the union of which constitutes a raindrop, is 
necessarily a better mirror than mist. Now it is obvious 
and has already been stated l that a mirror of this kind 
renders the colour of an object only, but not its shape. 

30 Hence it follows that when it is on the point of raining and 
the air in the clouds is in process of forming into raindrops 
but the rain is not yet actually there, if the sun is opposite, or 
any other object bright enough to make the cloud a mirror 
and cause the sight to be reflected to the object then 2 th-2 
reflection must render the colour of the object without its 
shape. Since each of the mirrors is so small as to be 

35 invisible and what we see is the continuous magnitude made 
up of them all. the reflection necessarily gives us a continu 
ous magnitude made up of one colour ; each of the mirrors 
contributing the same colour to the whole. 3 We may 
deduce that since these conditions are realizable there wil! 

30 be an appearance due to reflection whenever the sun and the 
cloud are related in the way described and we are between 
them. But these are just the conditions under which the 
rainbow appears. So it is clear that the rainbow is 
a reflection of sight to the sun. 

So the rainbow always appears opposite the sun whereas 

35 the halo is round it. They are both reflections, but the 

374 a rainbow is distinguished by the variety of its colours. The 

reflection in the one case is from water which is dark and 

from a distance ; in the other from air which is nearer and 

lighter in colour. White light through a dark medium or 

on a dark surface (it makes no difference) looks red 4 . We 

5 know how red the flame of green wood is : this is because 

so much smoke is mixed with the bright white firelight : so, 

too, the sun appears red through smoke and mist. That is 

why in the rainbow reflection the outer circumference is 

1 372 a 34- 

2 Omit TC (1. 24) with EJFHN. 3 Cp. a 19, 374*34. 
4 De Sensu, 440* 10 ; De Col. 792* 9. 

BOOK III. 4 374 a 

red (the reflection being from small particles of water 1 ),but 
not in the case of the halo. The other colours shall be ex- 10 
plained later. Again, a condensation of this kind cannot 
persist in the neighbourhood of the sun : it must either turn 
to rain or be dissolved, but opposite to the sun there is an 
interval during which the water is formed. If there were 
not this distinction haloes would be coloured like the rain- 15 
bow. Actually no complete or circular halo presents this 
colour, only small and fragmentary appearances called 
rods . 2 But if a haze due to water or any other dark 
substance formed there we should have had, as we main 
tain 3 , a complete rainbow like that which we do find round 
lamps. A rainbow appears round these in winter, generally 20 
with southerly winds. Persons whose eyes are moist sec it 
most clearly because their sight is weak and easily reflected. 
It is due to the moistness of the air and the soot which the 
flame gives off and which mixes with the air and makes it 25 
a mirror, 4 and to the blackness which that mirror derives 
from the smoky nature of the soot. The light of the lamp 
appears as a circle which is not white but purple. It shows 
the colours of the rainbow ; but because the sight that is 
reflected is too weak 5 and the mirror too dark, red is 
absent. The rainbow that is seen when oars are raised out 30 
of the sea involves the same relative positions as that in 
the sky, 6 but its colour is more like that round the lamps, 
being purple rather than red. The reflection is from very 
small particles continuous with one another, and in this case 
the particles are fully formed water. We get a rainbow, 35 
too, if a man sprinkles fine drops in a room turned to the 374 b 
sun so that the sun is shining in part of the room and 
throwing a shadow in the rest. Then if one man sprinkles 
in the room, another, standing outside, sees a rainbow where 
the sun s rays cease and make the shadow. Its nature and 5 

1 And water being dark. 

2 Wind galls , weather galls , wind dogs . 

3 Cf. a I above. Read X<>>/xi/ in 1. 19 with the MSS. 

4 Read Tore yap yiverai evoTrrpov (1. 25) as a parenthesis with 

5 It is bound to be weak by lamplight. 

6 i. e. the observer is between the sun and the bow. 


colour is like that from the oars and its cause is the same, 
for the sprinkling hand corresponds to the oar. 

That the colours of the rainbow are those we described l 
and how the other colours come to appear in it will be clear 
from the following considerations. We must recognize, as 

10 we have said, 2 and lay down : first, that white colour on 
a black surface or seen through a black medium gives red ; 
second, that sight when strained to a distance :{ becomes 
weaker and less ; third, that black is in a sort the negation 
of sight : an object is black because sight fails ; so every 
thing at a distance looks blacker, because sight does not 

15 reach it. The theory of these matters belongs to the 
account of the senses, which are the proper subjects of such 
an inquiry ; we need only state about them what is neces 
sary for us. At all events, that 4 is the reason why distant 
objects and objects seen in a mirror look darker and 

20 smaller and smoother, and why the reflection of clouds in 
water is darker than the clouds themselves. This latter is 
clearly the case: the reflection diminishes the sight that 
reaches them. It makes no difference whether the change 
is in the object seen or in the sight, 5 the result being in 
either case the same. The following fact further is worth 

25 noticing. When there is a cloud near the sun and we look 
at it it does not look coloured at all but white, but when 
we look at the same cloud in water it shows a trace of 
rainbow colouring. Clearly, then, when sight is reflected it 
is weakened and, as it makes dark look darker, so it makes 

30 white look less white, changing it and bringing it nearer to 
black. When the sight is relatively strong the change is to 
red ; the next stage is green, and a further degree of weak 
ness gives violet. No further change is visible, but three com 
pletes the series of colours (as we find three does in most 
other things ), and the change into the rest is imperceptible 

1 372*7, cp. 375 a 28 below. 

2 374 a 3 % 

3 Read anorfivo^rri in 1. II with JF Al. Ol. 

4 Because sight fails. 

5 i. e. whether the object is actually farther from the eye in space or 
whether (owing to reflection) the sight travels to it by a longer route. 

6 Cp. De Cae/0, 268* 9. 

BOOK III. 4 374 1 

to sense. 1 Hence also the rainbow appears with three 
colours ; this is true of each of the two, but in a contrary way. 375* 
The outer band of the primary rainbow is red : for the largest 
band reflects most J sight to the sun, and the outer band is 
largest. The middle band and the third go on the same 
principle. So if the principles we laid down 3 about the 
appearance of colours are true the rainbow necessarily has 5 
three colours, and these three and no others. The appear 
ance of yellow is due to contrast, for the red is whitened by 
its juxtaposition with green. We can see this from the fact 
that the rainbow is purest when the cloud is blackest ; and 10 
then the red shows most yellow. (Yellow in the rainbow 
comes between red and green.) So the whole of the red 
shows white by contrast with the blackness of the cloud 
around : for it is white compared to the cloud and the 
green. 4 Again, 5 when the rainbow is fading away G and the 
red is dissolving, the white cloud is brought into contact 15 
with the green and becomes yellow. But the moon rainbow 
affords the best instance of this colour contrast. It looks 
quite white : this is because it appears on the dark cloud and 
at night. So, just as fire is intensified by added fire, black 20 
beside black makes that which is income degree white look 
quite white. 7 Bright dyes too show the effect of contrast. 
In woven and embroidered stuffs the appearance of colours 8 
is profoundly affected by their juxtaposition with one 
another (purple, for instance, appears different on white and 25 
on black wool), and also by differences of illumination. Thus 
embroiderers say that they often make mistakes in their 
colours when they work by lamplight, and use the wrong ones. 

1 The meaning of this clause seems to be that no further weakening 
of sense gives rise to any more colours. 

3 There is no sense in this, but the nonsense is probably Aristotelian. 

3 374 b 9 above, 

4 We must apparently supply the step : white and green gives 
yellow; as Al. does. The argument is: the blacker the cloud, the 
whiter the red and the greater the contrast with green, and therefore 
the more yellow the appearance of the rainbow. 

6 The red shows most yellow. 

6 Omit f yyimmo (1. 15) with E 1 A1. Ol. (lemma). 

7 Omit TOVTO 6 earl TO <$>ou>iK.oi>v (1. 2i) as a gloss due to someone 
who thought A. was referring to the outer band of the moon rainbow 
only. The words are incompatible with \ev<r] nd^rrav (1. 1 8). 

8 Omit (via in 1. 25 with JFHN Ol. 

645.21 G 


We have now shown why the rainbow has three colours 
and that these are its only colours. 1 

30 The same cause 2 explains the double rainbow and the 
faintness of the colours in the outer one and their inverted 
order. When sight is strained to a great distance the 
appearance of the distant object is affected in a certain way : 
and the same thing holds good here. 3 So the reflection 
375 b from the outer rainbow is weaker because it takes place 
from a greater distance and less of it reaches the sun, and so 
the colours seen are fainter. Their order is reversed because 

y Red ; 6 - Green ; e = Violet ; $ =Yclbu> 

more 4 reflection reaches the sun from the smaller, inner 

5 band. For that reflection is nearer to our sight which is 

reflected from the band which is nearest to the primary 

rainbow. Now the smallest band in the outer rainbow is that 

which is nearest, and so it will be red ; and the second and 

the third will follow the same principle. Let B be the outer 

10 rainbow, A the inner one ; let T stand for the red colour, 

A for green, E for violet ; yellow appears at the point Z. 

Three rainbows or more are not found because even the 

second is fainter, so that the third reflection can have no 

15 strength whatever and cannot reach the sun at all. 

The rainbow can never be a circle nor a segment of 5 
a circle greater than a semicircle. The consideration of 
the diagram 5 will prove this and the other properties of the 

1 i. e. the only ones directly due to reflection ; any others being due to 

2 i. e. reflection and the consequent weakening of sight the remoter the 
reflection is. The theory (though Alexander misunderstands it) evidently 
is that the second bow is an indirect reflection from the first, but the 
whole passage to the end of the chapter is obscure and probably corrupt. 

3 Cp. 374 22. * Read TrXftco with E 2 JF 2 HN and apparently Al. 

6 The figure is incorrectly drawn : KI1M should be ) a right-angle ; 
but it probably represents what Aristotle had in mind (Poske). The 

BOOK III. 5 375 " 

Let A be a hemisphere resting on the circle of the 
horizon, let its centre be K and let H be another point 20 
appearing on the horizon. Then, if the lines that fall in 
a cone from K have HK as their axis, and, K and M being 
joined, the lines KM are reflected from the hemisphere to 
H over the greater angle, 1 the lines from K will fall on the 
circumference of a circle. If the reflection takes place when 35 
the luminous body is rising or setting the segment of the 
circle above the earth which is cut off by the horizon will be 
a semicircle ; if the luminous body is above the horizon it 

will always be less than a semicircle, and it will be smallest 
when the luminous body culminates. 

First let the luminous body be appearing on the horizon 30 
at the point II, and let KM be reflected to II, and let the 
plane in which A is,- determined by the triangle IIKM; 5 
be produced. Then the section of the sphere will be 
a great circle. Let it be A (for it makes no difference 
which 4 of the planes passing through the line MK and 
determined by the triangle KMII 5 is produced). Now 376* 
the lines drawn from II and K to a point on the semicircle A 
are in a certain ratio to one another, and no lines drawn 
from the same points to another point on that semicircle can 

circle part of which is dotted stands for the meridian ; the circle HMPN 
for another great circle of the sphere, passing through H (the rising 
sun) and M (a point in the cloud) ; the curve MN for a semicircle in 
aplane at right angles to the plane of HMPN. 

1 HKM. 

2 A, originally a hemisphere (1. 19), is now used for a great circle 
of the whole sphere, and presently (376* 2) for the half of that circle 
which is above the horizon. 

3 Read < o> in 1. 32. 

4 Read OTTOIOVOVV in 1. 34 with FHN Al. Ol. 

6 Only one plane passes through a particular triangle KMH. 
But the A KMH may be imagined as rotating round HK, and 
the plane determined by any one of its positions would do equally 

G 2 


have the same ratio. For since both the points H and K 
and the line KH are given, 1 the line MH will be given too; 
consequently the ratio of the line MH to the line MK will 
5 be given too. So M will touch a given circumference. 
Let this be NM. Then the intersection of the circum 
ferences 2 is given, and the same ratio cannot hold between 
lines in the same plane drawn from the same points to any 
other circumference but MN. 3 

10 Draw a line AB outside of the figure and divide it so that 
A:B = MH:MK. But MH is greater than MK since the 
reflection of the cone is over the greater angle (for it sub 
tends the greater angle of the triangle KMH). Therefore 

15 A is greater than B. Then add to B a line Z such that 
B 4- Z : A = A : B. Then make another line KH having the 
same ratio to B as KH has to Z, and join MIT. 

Then H is the pole of the circle on which the lines from 

20 K fall. For the ratio of A to HM is the same as that of 
Z to KH and of B to KH. If not, let A be in the same 
ratio to a line indifferently lesser or greater than HM, and 
let this line be HP. Then HK and KH and HP will have 
the same ratios to one another as Z, B, and A. 4 But the 
ratios between Z, B, and A were such that Z -f B : A A : B. 

25 Therefore nUiHP^nPiHK. Now, if the points K, H 
be joined with the point P by the lines IIP, KP. these lines 
will be to one another as HH is to HP, for the sides of the 
triangles HHP, KPH about the angle H are homologous. 

30 Therefore, HP 5 too will be to KP as HH is to HP. But 
this is also the ratio of MH to MK, for 6 the ratio both of 
HH to HP and of MH to MK is the same as that of A to 
B- Therefore, from the points II, K there will have been 
drawn lines with the same ratio to one another, not only to 
the circumference MN but to another point as well, which 
is impossible. Since then A cannot bear that ratio to any 

1 Delete the comma after dcdorat and insert a comma after KH (1. 4). 

2 i. e. of the great circle inclined to the horizon and now called A 
and the circle forming the base of the cone. 

3 Read XX ?/ Se ye (]F l Ol. (lemma), aXXy 8 f yn ,) rj rf, MN (E 1 
Ol. (lemma)) in 1. 8. Cp. b 2. 

4 Read ZBA twice with E! Al. 

5 Read ^ HP with J rec. Al. Ol. (17 p E,). 

6 Read rovrov rov \6yov (JFHN Al.), ov yap (] Al.) in 1. 32. 

BOOK III. 5 376 b 

line either lesser or greater than FIM (the proof being in 
either case the same), it follows that it must stand in that 5 
ratio to Mil itself. Therefore as MIT is to UK so HH 
will be to MH and finally MH to MK. 

If, then, a circle be described with n as pole at the 
distance Mil it will touch all the angles which the lines 
from H and K : make by their reflection. If not, it can be 10 
shown, as before, that lines drawn to different points in the 
semicircle will have the same ratio to one another, which 
was impossible. If, then, the semicircle A be revolved 
about the diameter HKn, the lines reflected from the 
points 2 H, K at the point M will have the same ratio, and 15 
will make the angle KMII equal, in every plane. Further, 
the angle which I1M 3 and Mn make with HIT will always 
be the same. So there are a number of triangles on lin 
and KI1 equal to the triangles IIMFI and KMII. Their 
perpendiculars will fall on HIT at the same point and will 
be equal. Let O be the point on which they fall. Then O 20 
is the centre of the circle, half of which, MN , is cut off by 5 
the horizon. 6 

Next let the horizon be ABF but let II have risen above 
the horizon. Let the axis now be I in. The proof will be 3 

1 Read dirb TOV H KU\ K in 1. 10, omitting KVK\OV. Al. read mro TOV K 
/cat H, Bag. OTTO TOV KH, and both, as well as Ol., omit KVK\OI>. By reading 
H KOI K the insertion of KUK\OV is explained. 

8 Read TO>V HK and irpos TU> in 1. 14 with (apparently) Al. 

3 Read HM in 1. 16 after Tannery. The MSS. read Hn : Bag. 
Vic. KIT. 

4 TO Tffp\ TTJV MN (1. 21) implies a confusion between the horizon and 
the great circle inclined to it (375 b 32). Ar. may have fallen into this 
confusion, but there is no trace of these words in Al. and perhaps they 
are a gloss. Or perhaps we should read TOV nepi rr\v MN (sc. KVK\OV). 

5 Read i in 1. 22 with FHN Al. 

9 The following passage (11. 22-28) is found in all the MSS. except 
the first hand of E and is recognized by Ol. But it is not recognized 
by Al. and is not found in Bag. The transition to oratio obliqua is 
suspicious ; the passage is irrelevant to the context and incoherent in 
itself and certainly an interpolation. 

For the sun does not get the better of the upper parts, but it does 
of those that lie near the earth, and there it dissolves the air. This is 
the reason why the rainbow does not form a complete circle. A rain 
bow due to the moon is found at night, but rarely. For the moon is 
not always full, and its light is too weak to get the better of the air 
(read (77) wore in 1. 26). The rainbow is most established where the 
sun is most overpowered : for there then remains in it most moisture. 


the same for the rest as before, but the pole Ul of the circle 
will be below the horizon AT since the point II has risen 
377 a above the horizon. But the pole, and the centre of the 
circle, 1 and the centre of that circle (namely HIT) which 
now determines the position of the sun 2 are on the same 
line. But since KII lies above the diameter AT, the centre 3 
5 will be at O on the line KIT below the plane of the circle 
Ar which determined the position of the sun before. So 
the segment ^T 4 which is above the horizon will be less 
than a semicircle. 6 For ^OTH was a semicircle and it has 
now been cut off by c the horizon Ar. So part of it, 7 Til, 
will be invisible when the sun has risen above the horizon, 

and the segment visible will be smallest when the sun is on 
10 the meridian 8 ; for the higher II is the lower the pole and 
the centre of the circle will be. 

In the shorter days after the autumn equinox there may 
be a rainbow at any time of the day, but in the longer days 
from the spring to the autumn equinox there cannot be 
15 a rainbow about midday. The reason for this is that when 
the sun is north of the equator the visible arcs of its course 
are all greater than a semicircle, and go on increasing, while 
the invisible arc is small, but when the sun is south of the 
equator the visible arc is small and the invisible arc great, 
and the farther the sun moves south of the equator the 

1 Which is the base of the cone. 

2 i. e. the great circle which would be the horizon if the sun were 
rising when it is at the point H. 

3 Of the circle which is the base of the cone. 

4 Read *Y in 1. 7 wjth EJHN. 

5 Comma after ^tKvicXiov (1. 7). 

6 Read M in 1. 8 with FHN. 

7 Read airov, eirapOcvms in 1. 9 with JFHN. 

8 Read ufa-rjpfipias in 1. 10 with JFHN. 

9 Comma after /u y, and colon after Tro/j/wrc/w (1. 19) with Busse- 

BOOK III. 5 377 a 

greater is the invisible arc. Consequently, in the days 20 
near the summer solstice, the size of the visible arc is such 
that before the point H reaches the middle of that arc, that 
is its point of culmination, the point fl is well below the 
horizon ; the reason for this being the great size of the 
visible arc, and the consequent distance of the point of 
culmination from the earth. But in the days near the 
winter solstice the visible arcs are small, and the contrary is 25 
necessarily the case : for the sun is on the meridian before 
the point H has risen far. 

6 Mock suns, and rods too, are due to the causes we have 
described. A mock sun is caused by the reflection of sight 30 
to the sun. Rods are seen when sight reaches the sun 
under circumstances like those which we described, 1 when 
there are clouds near the sun and sight is reflected from some 
liquid surface to the cloud. Here the clouds themselves 
are colourless when you look at them directly, but in the 377 b 
water they are full of rods. The only difference is that in 
this latter case the colour of the cloud seems to reside in 
the water, but in the case of rods on the cloud itself. Rods 
appear when the composition of the cloud is uneven, dense 5 
in part and in part rare, and more and less watery in different 
parts. Then the sight is reflected to the sun : the mirrors 
are too small for the shape of the sun to appear, but, the 
bright white light of the sun, to which the sight is reflected, 
being seen on the uneven mirror, its colour appears partly 
red, partly green or yellow. It makes no difference 10 
whether sight passes through or is reflected from a medium 
of that kind ; the colour is the same in both cases ; if 
it is red in the first case it must be the same in the 

Rods then are occasioned by the unevenncss of the 
mirror as regards colour, not form. The mock sun, on the 15 
contrary, appears when the air is very uniform, and of the 
same density throughout. This is why it is white : 
the uniform character of the mirror gives the reflection 
in it a single colour, while the fact that the sight is reflected 


in a body and is thrown on the sun all together by the mist, 

20 which is dense and watery though not yet quite water, 
causes the sun s true colour to appear just as it does when 
the reflection is from the dense, smooth surface of copper. 
So the sun s colour being white, the mock sun is white too. 
This, too, is the reason why the mock sun is a surer sign of 

25 rain than the rods ; it indicates, 1 more than they do, that 
the air is ripe for the production of water. Further a mock 
sun to the south is a surer sign of rain than one to the 
north, for the air in the south is readier to turn into water 
than that in the north. 

Mock suns and rods are found, as we stated, 2 about 
sunset and sunrise, not above the sun nor below it, but 

30 beside it. They are not found very close to the sun, nor 
very far from it, for the sun dissolves the cloud if it is near, 
but if it is far off the reflection cannot take place, since 
sight weakens when it is reflected from a small mirror to 
a very distant object. (This is why a halo is never found 
378* opposite to the sun.) If the cloud is above the sun and 
close to it the sun will dissolve it : if it is above the sun 
but at a distance the sight is too weak for the reflection to 
take place, and so it will not reach the sun. But at the 
side of the sun, 3 it is possible for the mirror to be at such 
an interval that the sun does not dissolve the cloud, and 
5 yet sight reaches it undiminished because it moves close to 
the earth 4 and is not dissipated 5 in the immensity of space. 
It cannot subsist below the sun because close to the earth 
the sun s rays would dissolve it, but if it were high up and 
the sun in the middle of the heavens, sight would be 
dissipated. Indeed, even by the side of the sun, it is not found 
when the sun is in the middle of the sky, for then the line of 

10 vision is not close to the earth, 6 and so but little sight reaches 
the mirror and the reflection from it is altogether feeble. 
Some account has now been given of the effects of the 

15 secretion above the surface of the earth ; we must go on 

1 Read o-^/zruVi in 1. 25 with Ej Al. Bag. 2 372* 10. 

3 Omit VTTO TOV rjXiov in 1. 3 with JFHN Al. 

4 Read rfj yfj in 1. 5 with Al. (T^ yiji> Ej). 

5 Read didcrnaadai ill 1. 6 with EJF^ 

6 Read TT/JO? rfj yfj in 1. 10 with (perhaps) Al. 

BOOK III. 6 378 

to describe its operations below, when it is shut up in the 
parts of the earth. 

Just as its twofold nature gives rise to various effects in 
the upper region, so here it causes two varieties of bodies. 
We rnaintain that there are two exhalations, one vaporous 
the other smoky, and there correspond two kinds of bodies 
that originate in the earth, fossiles and metals. The heat 20 
of the dry exhalation is the cause of all fossiles . Such 
are the kinds of stones that cannot be melted, and realgar, 
and ochre, and ruddle, and sulphur, and the other things 
of that kind, most fossiles being either coloured lye or, 25 
like cinnabar, a stone compounded of it. The vaporous 
exhalation is the cause of all metals, those bodies which 
are either fusible or malleable such as iron, copper, gold. 
All these originate from the imprisonment of the vaporous 
exhalation in the earth, and especially in stones. Their 30 
dryness compresses it, and it congeals just as dew or 
hoar-frost does when it has been separated off, though in the 
present case the metals are generated before that segregation 
occurs. Hence, they are water in a sense, and in a sense 
not. Their matter was that which might have become 
water, but it can no longer do so : l nor are they, like 
savours, due to a qualitative change in actual water. Copper 
and gold are not formed like that, but in every case the 
evaporation congealed before water was formed. Hence, 
they all (except gold) arc affected by fire, and they possess 
an admixture of earth ; for they still contain the dry 

This is the general theory of all these bodies, but we 5 
must take up each kind of them and discuss it separately. 


I WE have explained that the qualities that constitute the 10 
elements are four, and that their combinations determine 
the number of the elements to be four. 

Two of the qualities, the hot and the cold, are active; 
two, the dry and the moist, passive. We can satisfy 

1 Read a colon after oi-<eVi (1. 34) with Ideler. 


ourselves of this by looking at instances. In every case 

15 heat and cold determine, conjoin, and change things of the 
same kind and things of different kinds, moistening, drying, 
hardening, and softening them. Things dry and moist. 
on the other hand, both in isolation and when present 
together in the same body are the subjects of that deter- 

?o mination and of the other affections enumerated. The 
account we give of the qualities when we define their 
characters shows this too. Hot and cold we describe as 
active, for congregating is essentially l a species of being 
active : moist and dry are passive, for it is in virtue of its 
being acted upon in a certain way that a thing is said to 

25 be easy to determine or difficult to determine . 2 So it 
is clear that some of the qualities are active and some 

Next we must describe the operations 3 of the active 
qualities and the forms taken by the passive. First of all, 
true becoming, that is, natural change, 4 is always the work 
of these powers and so is the corresponding natural destruc- 

30 tion ; and this becoming and this destruction are found in 
plants and animals and their parts." True natural becoming 
is a change introduced by these powers into the matter 
underlying a given thing when they are in a certain ratio 
to that matter, 6 which is the passive qualities we have 
379 a mentioned. When the hot and the cold are masters of the 
matter they generate a thing : if they are not, and the 
failure is partial, the object is imperfectly boiled 7 or other 
wise unconcocted. But the strictest general opposite of 
true becoming is putrefaction. All natural destruction is on 
the way to it, as are, for instance, growing old or growing 

5 dry. Putrescence is the end of all these things, 8 that is of 

1 Read ontp in 1. 23 with E Al. Vic. 

2 Colon after <WTO)V in 1. 25 (Bonitz). r/ . . . (WT&V (11. 13-25) is 
parenthetical. Colon after (TiWo-T^Kev (1. 20). 

3 Read as in 1. 27 with HN and perhaps Al. 

4 As distinguished from the making of artificial objects. 

c Hut not only in them. The statement is universally true of homo 
geneous HIKTU ; cp. the reference to sea-water 379 b 4- 

6 There should be a comma after \6yov (1. 33). 

7 Read uoXwais in 1. 2 with EJFHN Al. 

8 Read TOVTVV anavrw with E a and cod. Par. suppl. 314 in 1. 5 for 
Ta>v uXAcoi> (nriivTtov. Bag. read t nrnvT<t)i> TOVT&V. JFHN read T(WTU>V as 

BOOK IV. i 379* 

all natural objects, except such as are destroyed by 
violence: 1 you can burn, for instance, flesh, bone, or any 
thing else, but the natural course of their destruction ends 
in putrefaction. Hence things that putrefy begin by being 
moist and end by being dry. For the moist and the dry 
were their matter, and the operation of the active qualities 10 
caused the dry to be determined by the moist. 

Destruction supervenes when the determined gets the 
better of the determining by the help of the environment 
(though in a special sense the word putrefaction is applied to 
partial destruction, when a thing s nature is perverted). Hence 
everything, except fire, is liable to putrefy ; for earth, water, 15 
and air putrefy, being all of them matter relatively to fire. 
The definition of putrefaction is : the destruction of the 
peculiar and natural heat in any moist subject by external 
heat, that is, by the heat of the environment. So since 
lack of heat is the ground of this affection and everything 
in as far 2 as it lacks heat is cold, both heat and cold will 20 
be the causes of putrefaction, which will be due indifferently 
to cold in the putrefying subject or to heat in the environ 

This explains why everything that putrefies grows drier 
and ends by becoming earth or dung. The subject s own 
heat departs and causes the natural moisture to evaporate 
with it, and then there is nothing left to draw in moisture, 
for it is a thing s peculiar heat that attracts moisture and 25 
draws it in. Again, putrefaction takes place less in cold 
than in hot seasons, for in winter the surrounding air and 
water contain but little heat and it has no power, but in 
summer there is more. Again, what is frozen does not 
putrefy, for its cold is greater than the heat of the air and 30 
so is not mastered, whereas what affects a thing does master 
it. Nor does that which is boiling or hot putrefy, for the 
heat in the air being less than that in the object does not 

well as TUV <"i\\<>>v, and Vic. shows traces of the same reading. TUV 
<i\\u)i> and TOVT&V are alternatives. aXXcoi/ implies a contrast which is 
wanting and Al. apparently did not read it. TUV <*\\a>v seems to be 
due to some one who thought that o-arrpuTtjs was something contrasted 
with crisis. 

1 There should be a comma after <f)0apfi (1. 6). 

2 Read # fit cV/W? in 1. 19 with E t Bag and probably Al. 


prevail over it or set up any change. So too anything that 

is flowing or in motion is less apt to putrefy than a thing 

35 at rest, for the motion set up by the heat in the air is 

379 b weaker than that pre-existing in the object, and so it causes 

no change. For the same reason a great quantity of a thing 

putrefies less readily than a little, for the greater quantity 

contains too much proper fire and cold for the corresponding 

qualities in the environment to get the better of. Hence, 

5 the sea putrefies quickly when broken up into parts, but 

not as a whole ; and all other waters likewise. Animals 

too are generated in putrefying bodies, because the heat 

that has been secreted, being natural, organizes the particles 

secreted with it. 

So much for the nature of becoming and of destruction. 

10 We must now describe the next kinds of processes which 2 
the qualities already mentioned set up in actually existing 
natural objects as matter. 

Of these concoction is due to heat ; its species are 
ripening, boiling, broiling. 1 Inconcoction is due to cold 
and its species are rawness, imperfect boiling, 2 imperfect 
broiling. (We must recognize that the things are not 

15 properly denoted by these words : the various classes of 
similar objects have no names universally applicable to 
them ; consequently we must think of the species enu 
merated as being not what those words denote but some 
thing like it.) Let us say what each of them is. Concoction 
is a process in which the natural and proper heat of an 
object perfects the corresponding passive qualities, which 

20 are the proper matter of any given object. 3 For when 
concoction has taken place we say that a thing has been 
perfected and has come to be itself. It is the proper heat 
of a thing that sets up this perfecting, though external 
influences may contribute in some degree to its fulfilment. 
Baths, for instance, and other things of the kind contribute 

1 For uniformity these words are used throughout the following 
chapters to render irenavo-ts, fyrjcris, onrqa-iSy though in various places 
other English words would be more appropriate. 

2 Read /xoAwtrir in 1. 14 with E a FHN 2 Al. Ol. 
s Read c fcaora> in 1. 20 with EJ F t Al. Bag. 

BOOK IV. 2 379 b 

to the digestion of food, but the primary cause is the 
proper heat of the body. In some cases of concoction 25 
the end of the process is the nature l of the thing nature, 
that is, in the sense of the formal cause and essence. In 
other cases it leads to some presupposed state which is 
attained when the moisture has acquired certain properties 
or a certain magnitude in the process of being broiled or 
boiled or of putrefying, 2 or however else it is being heated. 
This state is the end, for when it has been reached the 
thing has some use and we say that concoction has taken 
place. Must is an instance of this, 3 and the matter in boils 30 
when it becomes purulent, and tears when they become 
rheum, and so with the rest. 4 

Concoction ensues whenever the matter, the moisture, 
is mastered. For the matter is what is determined by the 
heat connatural to the object, and as long as the ratio 35 
between them exists in it a thing maintains its nature. 
Hence things like the liquid and solid excreta and ejecta in 38o a 
general are signs of health, and concoction is said to have 
taken place in them, for they show that the proper heat has 
got the better of the indeterminate matter. 

Things that undergo a process of concoction necessarily 
become thicker and hotter, for the action of heat is to make 
things more compact, thicker, and drier. 5 

This then is the nature of concoction : but inconcoction is 
an imperfect state due to lack of proper heat, that is, to cold. 
That of which the imperfect state is, is the corresponding 
passive qualities which are the natural matter of anything. 

So much for a definition of concoction and inconcoction. 10 

3 Ripening is a sort of concoction ; for we call it ripening 
when there is a concoction of the nutriment in fruit. And 
since concoction is a sort of perfecting, the process of ripening 
is perfect when the seeds in fruit are able to reproduce the 

1 Digestion proper or the ripening of fruit (380*25) subserves the 
perfecting of what is a * natural organic thing in a sense in which 
pus and rheum are not natural organic things. This is the distinction 
which A. is trying to draw. 

2 We should expect ncrraivopfvov ripening , as Thurot points out. 

3 i.e. when it * ripens and becomes wine. 4 Cp. n. I. 


15 fruit in which they are found ; for in all other cases as well 
this is what we mean by * perfect . This is what ripening 
means when the word is applied to fruit. However, many 
other things that have undergone concoction are said to be 
1 ripe , the general character of the process being the same, 
though the word is applied by an extension of meaning. 
The reason for this extension is, as we explained before, 1 
that the various modes in which natural heat and cold per 
fect the matter 2 they determine have not special name*- 

20 appropriated to them. In the case of boils and phlegm, and 
the like, the process of ripening is the concoction of the 
moisture in them by their natural heat, for only that which 
gets the better of matter can determine it. 3 So everything 
that ripens is condensed from a spirituous into a watery 
state, and from a watery into an earthy state, and in general 

25 from being rare becomes dense. In this process the nature 
of the thing that is ripening incorporates some of the matter 
in itself, 4 and some it rejects. So much for the definition of 

Rawness is its opposite and is therefore an imperfect 
concoction of the nutriment in the fruit, namely, of the un 
determined moisture. Consequently a raw thing is either 
spirituous or watery or contains both spirit and water. 

30 Ripening being a kind of perfecting, rawness will be an im 
perfect state, and this state 5 is due to a lack of natural heat 
and its disproportion to the moisture that is undergoing the 
process of ripening. (Nothing moist ripens without the 
admixture of some dry matter : water alone of liquids 6 
38o b does not thicken.) 7 This disproportion may be due either 
to defect of heat or to excess of the matter to be determined : 
hence the juice of raw things is thin, cold rather than hot, 
and unfit for food or drink. Rawness, like ripening, is used 
5 to denote a variety of states. Thus the liquid and solid 
excreta and catarrhs are called raw for the same reason, for 

1 379 b 14- 2 i- e - tne nioist and the dry. 

3 And the natural heat is that which can master the moist. 

4 Read alrr^v in 1. 26. r< Read 6 ;/ arc Xetn in 1. 31 with JFHN. 

6 Cp. 383* 12 and note, and 382 b 13. 

7 This sentence interrupts the connexion and would be more in 
place at 1. 3 (Vic.). 

BOOK IV. 3 380 

in every case the word is applied to things because their 
heat has not got the mastery in them and compacted them. 
If we go further, brick is called raw and so is milk and 
many other things too when they are such as to admit of 
being changed and compacted by heat but have remained 
unaffected. Hence, while we speak of boiled* water, we 10 
cannot speak of raw water, since it does not thicken. We 
have now defined ripening and rawness and assigned their 

Boiling is, in general, a concoction by moist heat of the 
indeterminate matter contained in the moisture of the thing 
boiled, and the word is strictly applicable only to things 
boiled in the way of cooking. The indeterminate matter, 15 
as we said, 1 will be either spirituous or watery. The cause 
of the concoction is the fire contained in the moisture ; 2 for 
what is cooked in a frying-pan is broiled : it is the heat out 
side that affects it and. as for the moisture in which it is 
contained, it dries this up and draws it into itself. But 
a thing that is being boiled behaves in the opposite way : 
the moisture contained in it is drawn out of it by the heat 20 
in the liquid outside. Hence boiled meats are drier than 
broiled ; for, in boiling, things do not draw the moisture into 
themselves, since the external heat gets the better of the 
internal : if the internal heat had got the better it would 
have drawn the moisture to itself. Not every body admits 
of the process of boiling : if there is no moisture in it, it does 25 
not (for instance, stones), nor does it if there is moisture in it 
but the density of the body is too great for it to be mastered, 
as in the case of wood. But only those bodies can be boiled 
that contain moisture which can be acted on by the heat con 
tained in the liquid outside. It is true that gold and wood 
and many other things are said to be boiled : but this is 
a stretch of the meaning of the word, though the kind of 
thing intended is the same,^ the reason for the usage being 30 
that the various cases have no names appropriated to them. 
Liquids too, like milk and must, are said to undergo a pro 
cess of boiling when the external fire that surrounds and 

1 a 2g. 2 In the moisture external to the thing boiled. 

3 Omit ov with E l (ov supra add. E x ) Bag. Cp. a 17. 


heats them changes the savour in the liquid into a given 
form, the process being thus in a way like what we have 
called boiling. 

381* The end of the things that undergo boiling, or indeed any 
form of concoction, is not always the same : some are meant 
to be eaten, some drunk, and some are intended for other 
uses ; for instance dyes, too, are said to be boiled \ l 

All those things then admit of boiling which can grow 
5 denser, smaller, or heavier ; also those which do that with 
a part of themselves and with a part do the opposite, dividing 
in such a way that one portion thickens while the other 
grows thinner, like milk when it divides into whey and curd. 2 
Oil by itself is affected in none of these ways, and therefore 
cannot be said to admit of boiling . Such then is the 

10 species of concoction known as boiling , and the process is 
the same in an artificial and 3 in a natural instrument, for 
the cause will be the same in every case. 

Imperfect boiling 4 is the form of inconcoction opposed to 
boiling. Now the opposite of boiling properly so called 6 is 
an inconcoction of the undetermined matter in a body due 
to lack of heat in the surrounding liquid. (Lack of heat 

15 implies, as we have pointed out, the presence of cold.) 6 The 
motion which causes imperfect boiling is different from that 
which causes boiling, for the heat which operates the con 
coction is driven out. The lack of heat is due either to the 
amount of cold in the liquid or to the quantity of moisture 7 
in the object undergoing the process of boiling. Where 
either of these conditions is realized the heat in the surround 
ing liquid is too great to have no effect at all, but too small 

1 This sentence interrupts the connexion, as Thurot points out, and 
is at least out of place, and oure 7reTTo/io/oi? is not easy to explain. 

2 Read rrveriav in 1. 7 with JF 3 HN, as in H.A. 522 b 5, 8, 9, n; 
P. A. 676*6, 8, n, 15, 18; G.A. 739 b 22, ;;2 a 25. TR-CTUI properly 
means rennet, but Ar. also uses it of the milk coagulated by rennet. 
Cp. P. A. 6;6 a 8 and Ogle s note. 

3 Read xai for fj in 1. 10 with EJFHN. 

4 Read poXwais in 1. 12 with J a FHN Al. Vic. 

6 Read (vavrla rfi npwTTj Xtx&iVi? in 1. 13. Bag. read rfj Trpwrr) and 
Vic. records the same reading as a variant. 

6 17 8 fvdfia . . . etprjTm (11. 14, 1 5) should be in a parenthesis (Thurot). 
The reference is to 379* 19. 

7 Cp. b l8. 

BOOK IV. 3 3 8i a 

to carry out the process of concoction uniformly and 
thoroughly. Hence things are harder when they are imper- 20 
fectly boiled l than when they are boiled, and the moisture 
in them more distinct from the solid parts. So much for the 
definition and causes of boiling and imperfect boiling. 2 

Broiling is concoction by dry foreign heat. Hence if 
a man were to boil a thing but the change and concoction 
in it were due, not to the heat of the liquid but to that of 25 
the fire, the thing will have been broiled and not boiled 
when the process has been carried to completion : if the 
process has gone too far we use the word * scorched to 
describe it. If the process leaves the thing drier at the end 
the agent has been dry heat. Hence the outside is drier 
than the inside, the opposite being true of things boiled. 
Where the process is artificial, broiling is more difficult than 30 
boiling, for it is difficult to heat the inside and the outside 
uniformly, since the parts nearer to the fire are the first to 
get dry and consequently get more intensely dry. In this 38l b 
way the outer pores contract and the moisture in the thing 
cannot be secreted but is shut in by the closing of the pores. 
Now broiling and boiling are artificial processes, but the 
same general kind of thing, as we said, 3 is found in nature 
too. The affections produced are similar though they lack 5 
a name ; for art imitates nature. For instance, the concoction 
of food in the body is like boiling, for it takes place in a hot 
and moist medium and the agent is the heat of the body. 
So, too, certain forms of indigestion are like imperfect boil 
ing. And it is not true that animals are generated in the 
concoction of food, as some say. Really they are generated 10 
in the excretion which putrefies in the lower belly, and they 
ascend afterwards. For concoction goes on in the upper 
belly but the excretion putrefies in the lower : the reason 
for this has been explained elsewhere. 4 

1 Read /K/uoXvoyzc i/u in 1. 21 with Erec. FHN Al. 

2 Read /ioXvi/o-i? in 1. 22 with E rec. FHN. 

3 379 b i4, 38o a i6. 

4 Alexander thinks the reference is to the Problems ; Heitz thinks it is 
to a lost work, Kepi rpo^y. The connexion seems to be this : if animals 
were generated in digestion, digestion would be a-J^ts-, and then it 
would be quite different from e^o-ir : so it is necessary to show that 
digestion is not a-fj^is. 


We have seen that the opposite of boiling is imperfect 
boiling : now there is something correspondingly opposed to 

15 the species of concoction called broiling, but it is more difficult 
to find a name for it. It would be the kind of thing that 
would l happen if there were imperfect broiling instead of 
broiling proper through lack of heat due to deficiency in the 
external fire or to the quantity of water in the thing under 
going the process. For then we should get too much he^t 
for no effect to be produced, but too little for concoction to 
take place. 

30 We have now explained concoction and inconcoction, 
ripening and rawness, boiling and broiling, and their 

We must now describe the forms taken by the passivo, 

qualities the moist and the dry. The elements of bodies, 

25 that is, the passive ones, are the moist and the dry ; the bodies 

themselves are compounded of them and whichever pre 

dominates determines the nature of the body ; thus some 

bodies partake more of the dry, others of the moist. All the 

forms to be described will exist either actually, or potentially 

and in their opposite : for instance, there is actual melting 

and on the other hand that which admits of being melted. 

Since the moist is easily determined and the dry deter- 

30 mined with difficulty, their relation to one another is like 

that of a dish and its condiments. The moist is what makes 

the dry determinate, and each serves as a sort of glue to the 

382 a other as Empedocles said in his poem on Nature, 2 ( glueing 

meal together by means of water . Thus the determined 

body involves them both. Of the elements earth is especially 

representative of the dry, water of the moist, 3 and therefore 

all determinate bodies in our world 4 involve earth and 

5 water. Every body shows the quality of that element 

which predominates in it. It is because earth and water are 

the material elements of all bodies that animals live in them 

alone and not in air or fire. 

Of the qualities of bodies hardness and softness are those 
10 which must primarily belong to a determined thing, for 

1 Read in 1. 16 olov yeVoiro with P^HN. 2 Diels, 21 B. 34. 

3 Contrast De Gen. et Corr. 33l a 4. 4 i.e. the sublunary region. 

BOOK IV. 4 382* 

anything made up of the dry and the moist is necessarily 
either hard or soft. Hard is that the surface of which does 
not yield into itself; soft that which does yield but not 1 by 
interchange of place : water, for instance, is not soft, for its 
surface does not yield to pressure or sink in but there is an 
interchange of place. Those things are absolutely hard and 
soft which satisfy the definition absolutely, and those things 15 
relatively so which do so compared with another thing. 
Now relatively to one another hard and soft are indefinable, 
because it is a matter of degree, but since all the objects of 
sense are determined by reference to the faculty of sense it 
is clearly the relation to touch which determines that which 
is hard and soft absolutely, and touch is that which we use 
as a standard or mean. So we call that which exceeds it 20 
hard and that which falls short of it soft. 

5 A body determined by its own boundary 2 must be either 
hard or soft ; for it either yields or does not. 

It must also be concrete : or it could not be so determined. 
So since everything that is determined and solid is either 
hard or soft and these qualities are due to concretion, all 2 5 
composite 3 and determined bodies must involve concretion. 
Concretion therefore must be discussed. 

Now 4 there are two causes besides r> matter, the agent and 
the quality brought about, the agent being the efficient 
cause, the quality the formal cause. Hence concretion and 
disaggregation, drying and moistening, must have these two 3 

But since concretion is a form of drying let us speak of382 b 
the latter first. 6 

As we have explained, the agent operates by means of 
two qualities and the patient is acted on in virtue of two 

1 Read /^ TG> for r&> \u\ in 1. 12. 

2 As contrasted with a liquid determined by the form of the vessel 
containing it. 

3 As distinct from elementary. 

4 Read fi? in 1. 27 with E 2 JHN Ol. (lemma). 

5 Read napd in 1. 28 with EJFHN Al. Ol. 

8 firfl . . . TTpwrov ( b I, 2) is clearly out of place. Transpose eVet. . . Trpwrci/ 
to follow vypaivea-Qat ( a 3 1) ; and read TO de TTCKTXOV in b 2 with var. Ji. The 
contrast to TTOICI ( a 32) comes in TO 8e TTUO-^OI/, and TO 8e nados . . . 
v ( a 33) is more or less parenthetical. 

H 2 


qualities : action takes place by means of heat or cold, and 
the quality is produced either by the presence or by the 
382 b absence of heat or cold ; but that which is acted upon is 
moist or dry or a compound of both. Water is the element 
characterized by the moist, earth that characterized by the 
dry, for these among the elements that admit the qualities 
moist and dry are passive. Therefore cold, too, being found 

5 in water and earth (both of which we recognize to be cold), 
must be reckoned rather as a passive quality. It is active 
only as contributing to destruction or incidentally in the 
manner described before 1 ; for cold is sometimes actually 
said to burn and to warm, but not in the same way as heat 
does, but by collecting and concentrating heat. 

10 The subjects of drying are water and the various watery 
fluids and those bodies which contain water either foreign 
or connatural. By foreign I mean like the water in wool, 
by connatural, like that in milk. The watery fluids aro 
wine, urine, whey, and in general those fluids which have no 
sediment or only a little, except where this absence of sedi 

15 ment is due to viscosity. For in some cases, 2 in oil anc 
pitch for instance, it is the viscosity which prevents any 
sediment from appearing. 

It is always a process of heating or cooling that dries 
things, but the agent in both cases is heat, either internal 01 
external. For even when things are dried by cooling, like 

20 a garment, where the moisture exists separately it is the 
internal heat that dries them. It carries off the moisture in 
the shape of vapour (if there is not too much of it), being itsell 
driven out by the surrounding cold. So everything is dried, 
as we have said, by a process either of heating or cooling, 
but the agent is always heat, cither internal or external, 

25 carrying off the moisture in vapour. By external heat 
I mean as where things are boiled : by internal where the 
heat breathes out and takes away and uses up its moisture. 3 
So much for drying. 

1 i. e. by ai/riTre/JiVrao-iy. Cp. 347 b 4~9- 

2 Omit pev in 1. 15 with JFHN. 

3 afaupeOfVTos (1. 26) as a genitive absolute, where the nominative 
would be more regular, is difficult. Perhaps we should read d 
(roO eVcrds), sc. fappov. So perhaps Al. 204. 7. 

BOOK IV. 6 382* 

6 Liquefaction is, first, condensation into water ; second, 
the melting of a solidified body. The first, condensation, 
is due to the cooling of vapour : l what melting is will 30 
appear from the account of solidification. 

Whatever solidifies is either water or a mixture of earth 
and water, and the agent is either dry heat or cold. Hence 
those of the bodies solidified by heat or cold which are 
soluble 2 at all are dissolved by their opposites. Bodies 383* 
solidified by the dry-hot are dissolved by water, which is the 
moist-cold, while bodies solidified by cold are dissolved by 
fire, which is hot. Some things seem to be solidified by 
water, e. g. boiled honey, 3 but really it is not the water but 5 
the cold in the water which effects the solidification. Aqueous 
bodies are not solidified by fire : for it is fire that dissolves 
them, and the same cause in the same relation cannot have 
opposite effects upon the same thing. Again, water solidi 
fies owing to the departure of heat ; so it will clearly be 

* dissolved by the entry into it of heat : cold, therefore, must 
be the agent in solidifying it. 

Hence aqueous bodies do not thicken when they soli- 10 
dify ; for thickening occurs when the moisture goes off and 
the dry matter comes together, but water is the only liquid 
that does not thicken. 4 Those bodies that are made up of 
both earth and water are solidified both by fire and by cold 
and in either case are thickened. The operation of the two 
is in a way the same and in a way different. Heat acts by 15 
drawing off the moisture, and as the moisture goes off in 
vapour the dry matter thickens and collects. Cold acts by 

1 Omit (Is vdup in 1. 30 with EJI^HN Ol. (lemma). 

2 Aristotle does not distinguish in this or the next chapter between 
solution (\vt(r6ai) and melting (TJ)IS) : they are treated indifferently 
as the correlate of rr/^ir. 

3 But cp. 385*1. 

4 Two points are confusedly intended: (l) because thickening = 
removal of moisture, solidification of aqueous bodies by cold (not 
involving removal of moisture) does not involve thickening ; (2) thicken 
ing involves dry matter that comes together ; aqueous bodies have no 
such matter (or too little, though Aristotle does not say this); . . aqueous 
bodies do not thicken. vSwp in the last clause (1. 12) must be taken 
to = TO. vdaros and to include olvos ovpov oppos (382 b i3), and is con 
trasted with TO. vyp, e.g. milk, blood (cp. 384*11-19), as containing 
(little or) no dry matter. The first line of thought is implied by 610 
(1. 10), the second by roiaCra (1. n). Cp. 380*33. 


driving out the heat, which is accompanied by the moisture 
as this goes off in vapour with it. Bodies that arc soft but 

20 not liquid do not thicken but solidify when the moisture 
leaves them, e. g. potter s clay in process of baking : but 
those mixed bodies that are liquid thicken besides solidify 
ing, like milk. Those bodies which have first been thickened 
or hardened by cold often begin by becoming moist : thus 
potter s clay at first in the process of baking steams and 

25 grows softer, and is liable to distortion in the ovens for that 

Now of the bodies solidified by cold which are made up 
both of earth and water but in which the earth preponderates, 
those which solidify by the departure of heat melt by heat 
when it enters into them again ; this is the case with frozen 

30 mud. But those which solidify by refrigeration, where all 
the moisture has gone off in vapour with the heat, 1 like iron 
and horn, cannot be dissolved except by excessive heat, but 
they can be softened though manufactured iron does 
melt, to the point of becoming fluid and then solidifying 
again. This is how steel is made. The dross sinks to the 
b bottom 2 and is purged away : when this has been done often 
and the metal is pure we have steel. The process is not 
repeated often because the purification of the metal involves 
great waste and loss of weight. But the iron that has less 
5 dross is the better iron. The stone pyrimachus? too, 
melts and forms into drops and becomes fluid ; after having 
been in a fluid state it solidifies and becomes hard again. 
Millstones, 4 too, melt and become fluid: when the fluid 
mass begins to solidify it is black but its consistency comes 
to be like that of lime. [Mud and earth, too, melt]/ 

1 Read vypov for Geppov in 1. 30 with E 2 . 

2 It does not, but Aristotle may have thought that it did, especially 
as the iron would be of the nature of earth. It is hard to make the 
text mean the opposite, which is true, with Ideler. Cp. Aetna 478 
qualem purgato cernes desidere ferro . 

3 Perhaps a sort of silex : silex pyromaque in Daremberg and 
Saglio, s.v.ferruw. 

4 Millstones were often made of various kinds of lava, especially 
basaltic lava. 

6 This sentence should be rejected with Thurot. It is disconnected : 
iri]\6s repeats a 29; yij without qualification is senseless in this con 

BOOK IV. 6 383 

Of the bodies which are solidified by dry heat some are 10 
insoluble, others are dissolved by liquid. Pottery and some 
kinds of stone that are formed out of earth burnt up by fire, 
such as millstones, 1 cannot be dissolved. Natron and salt 
are soluble by liquid, but not all liquid but only such as is 
cold. 2 Hence water and any of its varieties melt them, but 
oil does not. For the opposite of the dry-hot is the cold-moist 15 
and what the one solidified the other will dissolve, and so 
opposites will have opposite effects. 

7 If a body contains more water than earth fire only thickens 
it : if it contains more earth fire solidifies it. Hence natron 
and salt and stone and potter s clay must contain more earth. 

The nature of oil presents the greatest problem. 3 If 20 
water preponderated in it, cold ought to solidify it ; if 
earth preponderated, then fire ought to do so. 4 Actually 
neither solidifies, but both thicken it. The reason is that it 
is full of air (hence it floats on the top of water, since air 25 
tends to rise). Cold thickens it by turning the air in it into 
water, for any mixture of oil and water is thicker than 
either. Fire and the lapse of time thicken and whiten it. 
The whitening follows on the evaporation of any water that 
may have been in it ; the thickening is due to the change of 30 
the air into water as the heat in the oil is dissipated. The 
effect in both cases is the same and the cause is the same, 
but the manner of its operation is different. Both heat 
and cold thicken it, but neither dries it (neither the sun nor 
cold dries oil), not only because it is glutinous but because it 

1 This seems to contradict 1. 7. The word there is at /zuXai, here 
oi /luXuu. Since millstones were made of a great variety of kinds of 
stone it is possible that Aristotle here meant by ot p.v\iai an entirely 
different kind of stone from the lava to which al /u Xru referred. If so, 
he expressed his meaning in a very clumsy way ; for he has given no 
means of finding out what sort of stone ot /^uXt at is meant to denote. 
But perhaps the word is corrupt. ?ot Mr}Xtot. Cp. Theophr. De Lap. 
ii. 14, iii. 21. The difficulty cannot be met by distinguishing r?}Kc<rd<u 
and \vf<r0ai with Ideler. 

2 Warm water, of course, is cold for the purpose of the argument. 

3 Cp. De Gen. An. 735** 13 sqq. 

4 Omit t^ft n-Xcoi/ in 1. 21 with EJHN Vic. Bag. ; omit us of n-uyoi and 
cor 6 KfajLos with EHN Al. 


contains air. Its glutinous nature prevents it from giving off 
vapour and so fire does not dry it or boil it off. 1 

Those bodies which are made up of earth and water may 
be classified according to the preponderance of either. 
There is a kind of wine, for instance, which both solidifies 2 

5 and thickens by boiling I mean, must. All bodies of this 
kind lose their water as they dry. That it is their water 
may be seen from the fact that the vapour from them con 
denses into water when collected. So wherever some sedi 
ment 3 is left this is of the nature of earth. Some of 
these bodies, as we have said, 4 are also thickened and dried 

10 by cold. For cold not only solidifies but also dries water, 
and thickens things by turning air into water. (Solidifying, 
as we have said, 5 is a form of drying.) Now those things 
that are not thickened by cold, but solidified, belong rather 
to water, e.g. wine, urine, vinegar, lye, c whey. But those 
things that are thickened (not by evaporation due to fire) 7 

15 are made up either of earth or of water and air : honey of 
earth, while oil contains air. Milk and blood, too, are 
made up of both water and earth, though earth generally 8 
predominates in them. So, too, are the liquids out of which 
natron and salt are formed ; and stones are also formed 
from some mixtures of this kind. Hence, if the whey has 
not been separated, it burns away if you boil it over a fire. 

20 But the earthy element in milk can also be coagulated by 
the help of fig-juice, if you boil it in a certain way as 

1 Omitting TO v8a>p (1. i) : this and the variant r6 eXaiov are rival 

2 And therefore comes under the heading of earth, whereas wine 
in general is water (382 b i3). You would expect the order to be 
thickens and solidifies , but tycrac is a sort of afterthought to make it 
clear that the nr)is is by heat and not by cold. But Aristotle is rather 
uncertain on the point. Cp. 385 I, 3S; b 9, 388 b I. 

3 Some sediment worth speaking of is meant as distinct from the 
little or none of 382 b i4. Aristotle is unsuccessfully trying to clear 
up the difficulty he has created by sometimes treating whey, wine, &c., 
as water (species of water, 382 b 13), which really involves their having 
no admixture of earth, when he knows that really they have some 
sediment, though not much. Cp. 388 b I. 


382" i. 

Koiu a, a lye of wood ashes. 

i. e. that are thickened by cold. 

Exceptions in 384* 24-9. 

BOOK IV. 7 384 

doctors do when they treat it with fig-juice, 1 and this is 
how the whey and the cheese are commonly separated. 
Whey, once separated, does not thicken, as the milk did, 
but boils away like water. Sometimes, however, there is 
little or no cheese in milk, and such milk is not nutritive 
and is more like water. The case of blood is similar : cold 25 
dries and so solidifies it. Those kinds of blood that do not 
solidify, like that of the stag, belong rather to water and 
are very cold. Hence they contain no fibres : for the fibres 
are of earth and solid, and blood from which they have been 
removed does not solidify. This is 2 because it cannot dry ; 
for what remains is water, just as what remains of milk 3 
when cheese has been removed is water. The fact that 
diseased blood will not solidify is evidence of the same thing, 
for such blood is of the nature of serum and that is phlegm 
and water, the nature of the animal having failed to get the 
better of it and digest it. 

Some of these bodies a are soluble, e. g. natron, some in 
soluble, e. g. pottery : of the latter, some, like horn, can be 
softened by heat, others, like pottery and stone, cannot. The 
reason is that opposite causes have opposite effects: con 
sequently, if solidification is due to two causes, the cold and 
the dry, solution must be due to the hot and the moist, 
that is, to fire and to water (these being opposites) : water 5 
dissolving what was solidified by fire alone, fire what was 
solidified by cold alone. Consequently, if any things 4 
happen to be solidified by the action of both, these are least 
apt to be soluble. Such a case we find where things have 
been heated and are then solidified by cold. When the 
heat in leaving them has caused most of the moisture 5 to 
evaporate, the cold so compacts these bodies together again 
as to leave no entrance even for moisture. 6 Therefore heat 10 
does not dissolve them (for it only dissolves those bodies 
that are solidified by cold alone), nor does water (for it does 

1 Cp. Dioscorides, ii. 77. 

2 Read m i/ in 1. 29 with JFHN Bag. 

3 Those made up of earth and water. 

* Read ei n for ci in 1. 6 with F and Henricus (eir tl Jj). 

fi Delete the comma after tgiuv (1. 9) and read a comma after \ryp6v. 

6 Cp. 3 83 a i 3 ,26. 


not dissolve what cold solidifies, but only what is solidified 
by dry heat). 1 But iron is melted by heat and solidified by 

15 cold. 2 Wood consists of earth and air and is therefore 
combustible but cannot be melted or softened by heat. (For 
the same reason it floats in water all except ebony. This 
does not, for other kinds of wood contain a preponderance 
of air, but in bkck ebony the air has escaped and so earth 
preponderates in it.) Pottery consists of earth alone because 

20 it solidified gradually in the process of drying. 3 Water 
cannot get into it, for the pores were only large enough to 
admit of vapour escaping: and seeing that fire solidified it, 
that cannot dissolve it either. 

So solidification and melting, their causes, and the kinds 
of subjects in which they occur have been described. 

All this makes it clear that bodies are formed by heat 8 
25 and cold and that these agents operate by thickening and 
solidifying. It is because these qualities fashion bodies that 
we find heat in all of them, and in some cold in so far as 
heat is absent. These qualities, then, are present as active, 
and the moist and the dry as passive, and consequently 
30 all four are found in mixed bodies. So water and 
earth are the constituents of homogeneous bodies both 
in plants and in animals and of metals such as gold, 
silver, and the rest water and earth and their respective 
exhalations shut up in the compound bodies, as we have 
explained elsewhere. 4 

385* All these mixed bodies are distinguished from one another, 
firstly by the qualities special to the various senses, that is, by 

1 This sentence should perhaps be omitted. There is an anacolu- 
tion ov& virbv&aTos and the general explanation given entirely ignores 
the more special account of the preceding sentence. The therefore 
is pointless (soThurot). Further c> 8e ai8^pns . . . n^ywrai (1. 14) follows 
much better on the sentence before. LI. 1 1-14 are really an alternative 
to 11. 7-11 and 11. 14, 15. , 

2 Omit oxrrf . . . tiXvrov (\\. 14, 15). There is no MS. authority for it, 
and it seems to have found its way into the texts through a misinter 
pretation of Alexander, who certainly did not read it. The clause runs : 
hence both are involved in its solidification : therefore it is insoluble 
(i. e. difficult to dissolve). This gloss may give the correct interpreta 
tion of the remark about iron. Iron is quoted as an instance of the 
process described in 11. 7, 8. Cp. 385*31. 

3 And therefore is insoluble. 

4 e.g. 378* I5~ b 6 in relation to metals. 

BOOK IV. 8 385 

their capacities of action. 1 (For a thing is white, fragrant, 
sonant, sweet, hot, cold in virtue of a power of acting on 
sense.) 2 Secondly by other more characteristic affections 
which express their aptitude to be affected : I mean, for 5 
instance, the aptitude to melt or solidify or bend and so 
forth, all these qualities, like moist and dry, being passive. 
These are the qualities that differentiate bone, flesh, sinew, 
wood, bark, stone and all other homogeneous natural 
bodies. Let us begin by enumerating these qualities ex- 10 
pressing the aptitude or inaptitude of a thing to be affected 
in a certain way. They are as follows : to be apt or inapt 
to solidify, melt, be softened by heat, be softened by water, 
bend, break, be comminuted, impressed, moulded, squeezed ; 15 
to be tractile or non-tractile, malleable or non-malleable, 
to be fissile or non-fissile, apt or inapt to be cut ; to be viscous 
or friable, compressible or incompressible, combustible or 
incombustible ; to be apt or inapt to give off fumes. These 
affections differentiate most bodies from one another. Let 
us go on to explain the nature of each of them. 

We have already given a general account of that which is 20 
apt or inapt to solidify or to melt, but let us return to them 
again now. Of all the bodies that admit of solidification 
and hardening, some are brought into this state by heat, 
others by cold. Heat does this by drying up their moisture, 
cold by driving out their heat. Consequently some bodies *5 
are affected in this way by defect of moisture, some by 
defect of heat : watery bodies by defect of heat, earthy bodies 
of moisture. Now those bodies that are so affected by 
defect of moisture are dissolved by water, unless like pottery 
they have so contracted that their pores are too small for 
the particles of water to enter. All those bodies in which 3 
this is not the case are dissolved by water, e.g. natron, salt, 
dry mud. Those bodies that solidified through defect of 
heat are melted by heat, e.g. ice, lead, copper. So much 
for the bodies that admit of solidification and of melting, 
and those that do not admit of melting. 

1 Omit *m before TW in 1. 2 with E (original reading) and HN V 

2 Delete the colon after &vi>aa-6at (1. 2). Aewoi/ . . . JTI is a parenthesis 


The bodies which do not admit of solidification are those 
which contain no aqueous moisture and are not watery, but 
in which heat and earth preponderate, like honey 1 and 
must 2 (for these are in a sort of state of effervescence), and 
those which do possess some water but have a preponderance 
5 of air, like oil and quicksilver, and all viscous substances 
such as pitch and birdlime. 3 

Those bodies admit of softening 4 which are not (like ice) 5 9 
made up of water, but in which earth predominates. All 
their moisture must not have left them (as in the case of 
natron and salt), nor must the relation of dry to moist in 

10 them be incongruous (as in the case of pottery). 6 They 
must be tractile (without admitting water) or malleable 
(without consisting of water), and the agent in softening 
them is fire. Such are iron and horn. 7 

Both of bodies that can melt and of bodies that cannot, 
som e do and some do not admit of softening in water. 
Copper, for instance, which can be melted, cannot be 
softened in water, whereas wool and earth can be softened 
in water, for they can be soaked. (It is true that though 

15 copper can be melted the agent in its case is not water, but 
some of the bodies that can be melted by water too such 
as natron and salt cannot be softened in water: for nothing 
is said to be so affected unless the water soaks into it and 
makes it softer.) Some things, on the other hand, such as 
wool and grain, can be softened by water though they cannot 
be melted. Any body that is to be softened by water must 
be of earth and must have its pores larger than the particles 

20 of water, and the pores themselves must be able to resist 
the action of water, whereas bodies that can be melted 
by water must have pores throughout. 8 

1 Cp. 383*5- 

2 Cp. 384 a 5, 3S7 b 9> 388 b I. 

3 Reading (TUT *<u) lt>s in 1. 5 with Al. Ol. 

4 /MaXKTos, that which can be softened by heat, as opposed 
that which can be softened by water. 

5 Omit nas yap Kpva-raXXcs in 1. 7 with E (original reading) 

6 Cp. a 28 and Theophr. de lgne< v. 42. 

7 Omit Ko.1 u\n in 1. 12 with Gesner. Cp. 384 b 15. 

8 OVTWV Se <TK\r)poTtpo)v (1. 20) must be corrupt, but the contrast 
intended is clear. If a body is rtyKrov (can be softened by water) 

BOOK IV. 9 385* 

[Why is it that earth is both melted and softened by 
moisture, while natron is melted but not softened ? 
Because natron is pervaded throughout by pores so that l 
the parts are immediately divided by the water, but earth 25 
has also pores 2 which do not connect 3 and is therefore 
differently affected according as the water enters by one or 
the other set of pores. 4 ] 

Some bodies 5 can be bent or straightened, like the reed 
or the withy, some cannot, like pottery and stone. Those 
bodies are apt to be bent and straightened which can 
change from being curved to being straight and from being 30 
straight to being curved, and bending and straightening 
consist in the change or motion to the straight or to a curve, 
for a thing is said to be in process of being bent whether it 
is being made to assume a convex or a concave shape. So 386* 
bending is defined as motion to the convex or the concave 
without a change of length. For if we added or to the 
straight , we should have a thing bent and straight at once, 
and it is impossible for that which is straight to be bent. 
And if all bending is a bending back or a bending down, 
the former being a change to the convex, the latter to the 5 
concave, a motion that leads to the straight cannot be 
called bending, but bending and straightening are two 
different things. These, then, are the things that can, and 
those that cannot be bent, and be straightened. 

Some things can be both broken and comminuted, others 
admit only one or the other. Wood, for instance, can be 
broken but not comminuted, ice and stone can be com- 10 
minuted but not broken, while pottery may either be coin- 
it must admit the water by certain pores or passages, the passages 
themselves remaining intact ; if it is TTJKTOV (soluble) the pores 
themselves yield to the action of the water: this is expressed rather 
illogically by saying that it has pores throughout. Obviously if it 
had pores in every direction it would already be dissolved into its 
ultimate particles. Read ovras vK\r]poT(povs with E rec. N rec. and 
perhaps Al. Ol. 

1 Omit yf in 1. 24 with JFHN. 

a Omit at in 1. 25 with EJHNj. 

3 i. c. are not in a straight line with one another, cp. Probl. 905*40. 

4 Aristotle might have contrasted hard and soft pores, or partial 
pores and pores throughout ; he mixes the two contrasts in the text 
we have. 

6 Omit TWV o-co/xaVo)!/ in 1. 27 with E l Ol. (lemma). 


minuted or broken. The distinction is this : breaking is 
a division and separation into large parts, comminution into 
parts of any size, but there must be more of them than two. 
Now those solids that have many pores not communicating 

15 with one another are comminuible (for the limit to their sub 
division is set by the pores), but those whose pores stretch 
continuously for a long way are breakable, while those 
which have pores of both kinds are both comminuible and 

Some things, e. g. copper and wax, are impressible, others, 
e.g. pottery and water, are not. The process of being 
impressed l is the sinking of a part of the surface of a thing 
in response to pressure or a blow, in general to contact. 

20 Such bodies are either soft, 2 like wax, where part of the 
surface is depressed while the rest remains, or hard, like 
copper. Non-impressible :>> bodies are either hard, like 
pottery (ijs surface does not give way and sink in), or liquid, 
like water (for though water does give way it is not in 
a part of it, for there is a reciprocal change of place of all its 

25 parts). Those impressibles that retain the shape impressed 
on them and are easily moulded by the hand are called 
plastic ; those that are not easily moulded, such as stone 
or wood, 4 or are easily moulded but do not retain the shape 
impressed, like wool or a sponge, are not plastic. The last 
group are said to be squeezable . Things are squeezable 
when they can contract into themselves under pressure, 

30 their surface sinking in without being broken and without 5 
the parts interchanging "position as happens in the case of 
water. (We speak of pressure when there is movement and 
386 b the motor remains in contact with the thing moved, of 
impact when the movement is due to the local movement of 
the motor.) Those bodies are subject to squeezing which 
have empty pores empty, that is, of the stuff of which the 
body itself consists and that can sink in upon the void 
spaces within them, or rather upon their pores. For some- 

1 Omit ptv in 1. 19 with all the MSS. 

2 Read /zaXaxa in 1. 2O with E (original reading) OI. Bag. 

3 Read *al (ro) cidXaara in 1. 22 with Thurot, and a full stop after 
XaX*os-. * Cp. b 23. 

5 Read KO.\ {/-?) in 1. 31 with Par. suppl. 314. 

BOOK IV. 9 36 b 

times the pores upon which a body sinks in are not empty 
(a wet sponge, for instance, has its pores full). But the 5 
pores, if full, must be full of something softer than the body 
itself which is to contract. 1 Examples of things squeezable 
are the sponge, wax, flesh. Those things are not squeezable 
which cannot be made to contract upon their own pores by 
pressure, either because they have no pores or because their 
pores are full of something too hard. Thus iron, stone, 10 
water and all liquids are incapable of being squeezed. 

Things are tractile when their surface can be made to 
elongate, for being drawn out is a movement of the surface, 
remaining unbroken, in the direction of the mover. Some 
things are tractile, e. g. hair, thongs, sinew, dough, birdlime, 
and some are not, e.g. water, stone. Some things are both 15 
tractile and squeezable, e.g. wool; in other cases the two 
qualities do not coincide ; phlegm, for instance, is tractile but 
not squeezable, and a sponge squeezable but not tractile. 

Some things are malleable, like copper. Some are not, 
like stone and wood. Things arc malleable when their 
surface can be made to move (but only in part) 2 both down- 20 
wards and sideways with one and the same blow : when 
this is not possible a body is not malleable. All malleable 
bodies are impressible, but not all impressible bodies are 
malleable, e.g. wood, though on the whole the two go 
together. Of squeezable things some are malleable and 
some not : wax and mud are malleable, wool is not. 3 

Some things are fissile, e.g. wood, some are not, e.g. 25 
potter s clay. A thing is fissile when it is apt to divide in 
advance of the instrument dividing it, for a body is said to 
split when it divides to a further point than that to 
which the dividing instrument divides it and the act of 
division advances : which is not the case with cutting. 
Those bodies which cannot behave like this are non-fissile. 30 
Nothing soft is fissile (by soft I mean absolutely soft and 
not relatively : for iron itself may be relatively soft) ; nor 
are all hard things fissile, but only such as are neither liquid 

1 Read avro in 1. 7 (airo E corr. N, eavrd JiHi, c auro J rec.). 

2 To exclude dj/TiTrfpi oracm. Cp. a 24. 

3 Omit ovd uSwp in 1. 25 after Vic. 


nor impressible nor comminuible. Such are the bodies 
that have the pores along which they cohere lengthwise and 
not crosswise. 

Those hard or soft solids are apt to be cut which do not 

5 necessarily either split in advance of the instrument or break 

into minute fragments when they are being divided. Those 

that necessarily do so and liquids cannot be cut. Some 

things can be both split and cut, like wood, though generally 

it is lengthwise that a thing can be split and crosswise that 

it can be cut. For, a body being divided into many parts, 

10 in so far as its unity is made up of many lengths it is apt to 

be split, in so far as it is made up of many breadths it is 

apt to be cut. 

A thing is viscous when, being moist or soft, it is 
tractile. Bodies owe this property to the interlocking of 
their parts when they are composed like chains, for then 
they can be drawn out to a great length and contracted 
again. Bodies that are not like this are friable. 
15 Bodies are compressible when they are squeezable and 
retain the shape they have been squeezed into l ; incom 
pressible when they are either inapt to be squeezed at all or 
do not retain the shape they have been squeezed into. 

Some bodies are combustible and some are not. Wood, 
wool, bone are combustible ; stone, ice are not. Bodies are 
20 combustible when their pores are such as to admit fire and 
their longitudinal pores contain moisture weaker than fire. 
If they have no moisture, or if, as in ice or very green wood, 
the moisture is stronger than fire, they are not com 

Those 2 bodies give off fumes which contain moisture, but 

in such a form that it does not go off separately in vapour 

when they are exposed to fire. For vapour is a moist 

25 secretion tending to the nature of air 3 produced from 

1 Cp. TrXnoru 386* 27 : the only difference seems to be that the 
plasta must be easily moulded while there is no such limitation to 
the TriXqra here. 

2 The text for the remainder of this chapter is particularly corrupt 
and uncertain. 

3 Omit KOI Trvevpa (1. 25) as a gloss due to a mistaken inference from 
1. 29. The words are inconsistent with Aristotle s theory of 

BOOK IV. 9 3 87 a 

a liquid by the agency of burning heat. Bodies that give 
off fumes give off secretions of the nature of air by the lapse 
of time : as they perish away they dry up or become earth. 
But the kind of secretion we are concerned with now differs 
from others in that it is not moist nor does it become wind l 
(which is a continuous flow of air in a given direction). 
Fumes are a common secretion of dry and moist together 30 
caused by the agency of burning heat. Hence they do not 
moisten things but rather colour them. 

The fumes of a woody body are called smoke. (I mean 
to include bones and hair and everything of this kind in the 
same class. For there is no name common to all the 
objects that I mean, but, for all that, these things are all in 
the same class by analogy. Compare what Empedocles 
says : They are one and the same, hair and leaves and the 
thick wings of birds and scales that grow on stout limbs. 2 ) 5 
The fumes of fat are a sooty smoke and those of oily sub 
stances a greasy steam. Oil does not boil away or thicken 
by evaporation 3 because it does not give off vapour but 
fumes. Water on the other hand does not give off fumes, 
but vapour. Sweet wine 4 does give off fumes, for it contains 
fat and behaves like oil. It does not solidify under the in- 10 
fluence of cold and it is apt to burn. Really it is not wine 
at all in spite of its name : for it does not taste like wine 
and consequently does not inebriate as ordinary wine does. 
It contains but little fumigablc stuff and consequently is in 

All bodies are combustible that dissolve into ashes, and 
all bodies do this that solidify under the influence either of 15 
heat or of both heat and cold ; for we find that all these 
bodies are mastered by fire. Of stones the precious stone 
called carbuncle 6 is least amenable to fire. 7 

Of combustible bodies some are inflammable and some 

1 i. e. it is different both from the moist and from the dry 

2 Diels, 21 B. 82. 3 Cp. 383^0. 

4 Cp. 380^32, 384*5, 3 88 l > i. 

5 Read <$ ?x in 1. 13 with JjFHN Bag. Al., and dvpiaatv with EJHN 
Al. Ol. The line of thought would be : dvpiavis implies moisture, a 23 ; 
so having little of it may = being dry and therefore inflammable. 

6 Cp. Theophr. De Lap. iii. 18. 7 Cp. a 19. 


are not, and some of the former are reduced to coals. Those 
20 are called inflammable which produce flame and those 
which do not are called non-inflammable . Those fumig- 
able bodies that are not liquid are inflammable, but pitch, 
oil, wax are inflammable in conjunction with other bodies 
rather than by themselves. Most inflammable are those 
bodies that give off smoke. 1 Of bodies of this kind 2 those 
that contain more earth than smoke are apt to be reducec 
to coals. Some bodies that can be melted are not in- 
25 flammable, e. g. copper ; and some bodies that cannot be 
melted are inflammable, e. g. wood ; and some bodies can 
be melted and are also inflammable, e.g. frankincense. The 
reason is that wood has its moisture all together and this is 3 
continuous throughout and so it burns up : whereas copper 
has it in each part but not continuous, and insufficient in 
30 quantity to give rise to flame. In frankincense it is dis 
posed in both of these ways. Fumigable bodies are 
inflammable when earth predominates in them and they are 
consequently such as to be unable to melt. These are in- 
388 a flammable because they are dry like fire. When this dry 
comes to be hot there is fire. This is why flame is burning 
smoke or dry exhalation. The fumes of wood are smoke, 
those of wax and frankincense and such-like, and pitch and 
whatever contains pitch or such-like, are sooty smoke, while 
5 the fumes of oil and oily substances are a greasy steam ; so 
are those of all substances which are not at all combustible by 
themselves because there is too little of the dry in them (the 
dry being the means by which the transition to fire is 
effected), but burn very readily in conjunction with some 
thing else. (For the fat is 4 just the conjunction of the oily 
with the dry.) So those bodies 5 that give off fumes, like 
oil and pitch, belong rather to the moist, but those that 
burn to the drv. c 

1 Because flame is burning smoke, 388 a 2. 

2 Inflammable bodies. 

3 Read o-wtxfs earn in 1. 28 with the MSS. 

4 Which does burn readily, P. A. 649*28. 

5 Omit TU>I> lypSav (1. 8), which is an alternative to vypov. 

6 Both classes are thought of as falling within the fumigables in the 
wide sense of 387* 23, b i . 

BOOK IV. 10 3 88 a 

5 Homogeneous bodies differ to touch by these affections 10 
and differences, as we have said. 1 They also differ in 
respect of their smell, taste, and colour. 

By homogeneous bodies I mean, for instance. 2 metals , 
gold, copper, silver, tin, iron, stone, and everything else of 
this kind and the bodies that are extracted from them ; 15 
also the substances found in animals and plants, for instance, 
flesh, bones, sinew, skin, viscera, hair, fibres, veins (these are 
the elements of which the non-homogeneous bodies like the 
face, a hand, a foot, and everything of that kind are made up), 
and in plants, wood, bark, leaves, roots, 3 and the rest like 

The homogeneous bodies, it is true, are constituted by 20 
a different cause, 4 but the matter of which they are com 
posed is the dry and the moist, that is, water and earth (for 
these bodies exhibit those qualities most clearly). The 
agents are the hot and the.cold, for they constitute and make 
concrete the homogeneous bodies out of earth and water 
as matter. Let us consider, then, which of the homogeneous 25 
bodies are made of earth and which of water, and which of 

Of organized bodies some are liquid, some soft, some 
hard. The soft and the hard are constituted by a process 
of solidification, 5 as we have already explained. 

Those liquids that go off in vapour are made of water, 
those that do not are either of the nature of earth, or a 3 
mixture either of earth and water, like milk, or of earth 
and air, like wood, 6 or of water and air. like oil. Those 
liquids which are thickened by heat are a mixture. (Wine 
is a liquid which raises a difficulty : for it is both liable to 388 b 
evaporation and it also thickens ; for instance ne\v wine 

1 385*8. 

2 Read mov ni Tf in 1. 13 with EJN Bag., and omit olov after /iTX- 
\fv6fji(va with all the MSS. and Bag. 

3 According to Aristotle s doctrine elsewhere, however, while wood 
and bark are homoeomerous (385* 9), leaves and roots are anomoeo- 
merous (De An. 4i2 b 2, 3). rnXXa 1. 19 ... <a( 1. 20 should perhaps be 
omitted with H, but this looks like an error due to homoeoteleuton. 
Aristotle is probably writing carelessly. 

4 sc. their ddos. 

5 Read (on) irji-ei in 1. 28 after Gessner. Cp. 382*25. 

6 Cp. 3 8 4 b i5- 

1 2 


does. The reason is that the word wine is ambiguous l 
and different wines behave in different ways. New wine 
is more earthy than old, and for this reason it is more apt 
to be thickened by heat and less apt to be congealed by 
5 cold. For it contains much heat and a great proportion of 
earth, as in Arcadia, where it is so dried up in its skins by 
the smoke that you scrape it to drink. If all wine has some 
sediment in it then it will belong to earth or to water 
according to the quantity of the sediment it possesses.) The 
liquids that are thickened by cold are of the nature of 
earth ; those that are thickened either by heat or by cole 
consist of more than one element, like oil and honey and 
sweet wine . 

10 Of solid bodies those that have been solidified by cold are 
of water, e. g. ice, snow, hail, hoar-frost. Those solidified by 
heat are of earth, e.g. pottery, cheese, natron, salt. Some 
bodies are solidified by both heat and cold. 2 Of this kind 
are those solidified by refrigeration, that is by the privation 
both of heat and of the moisture which departs with the 

15 heat. For salt and the bodies that are purely of earth 
solidify by the privation of moisture only, ice by that of 
heat only, these bodies by that of both. So both the active 
qualities and both kinds of matter were involved in the 
process. Of these bodies those from which all the 
moisture has gone are all of them of earth, like pottery 3 or 
amber. (For amber, also, and the bodies called tears are 

20 formed by refrigeration, like myrrh, frankincense, gum. 
Amber, too, appears to belong to this class of things : the 
animals enclosed in it show that it is formed by solidification. 
The heat is driven out of it by the cold of the river and 
causes the moisture to evaporate with it, as in the case of 
honey when it has been heated and is immersed in water.) 

25 Some of these bodies cannot be melted or softened ; for in 
stance, amber and 4 certain stones, e.g. the stalactites in caves. 

1 Read (tV) ivi in 1. 2 with JFN. 

2 Cp. 383* 13. Bekker s punctuation is misleading, 6Va d* ITT apfyolv 
(1. 13) is taken up by oo-coi ovv arrav (1. 1 8) and oo-a 5f ^ o\a (1. 3) 
From roiuCra 8 (1. 13) to K<U fl\ (v **?$*> (! 1 7) is a parenthesis. 

3 The words KU\ yap to egar/i/fti TO iypov (11. 19-24) are a parenthesis 
and there should therefore be no full stops after K(>/i/u and vy^ov. 

4 Reading *ai for fj in 1. 25 with JFH Al. 

BOOK IV. 10 3 88 l 

(For these stalactites, too, are formed in the same way : the 
agent is not fire, but cold which drives out the heat, which, 
as it leaves the body, 1 draws out the moisture with it : in 
the other class of bodies 2 the agent is external fire.) In 
those from which the moisture has not wholly gone earth 30 
still preponderates, but they admit of softening by heat, 
e.g. iron and horn. 3 

Now since we must include among meltables those 
bodies which are melted by fire, these contain some water : 
indeed some of them, like wax, are common to earth and 
water alike. But those that are melted by water are of 389* 
earth. Those that are not melted either by fire or water 
are of earth, or of earth and water. 

Since, then, all bodies are either liquid or solid, and since 
the things that 4 display the affections we have enumerated 
belong to these two classes and there is nothing inter 
mediate, it follows that we have given a complete account 
of the criteria for distinguishing whether a body consists of 5 
earth or of water or of more elements than one, and 
whether fire was the agent in its formation, or cold, or 

Gold, then, and silver and copper and tin and lead and 
glass and many nameless stones are of water : for they are ro 
all melted by heat. Of water, too, are some wines and 
urine and vinegar and lye and whey and serum : for they 
are all congealed by cold. In iron, horn, nails, bones, 
sinews, wood, hair, leaves, bark, earth preponderates. So, 
too, in amber, myrrh, frankincense, and all the substances 
called tears , and stalactites, and fruits, such as leguminous 15 
plants and corn. For things of this kind are, to a greater 
or less degree, of earth. For of all these bodies some admit 
of softening by heat, the rest give off fumes and are formed 

1 Read UVTWV for avrov in 1. 29. 

2 e. g. salt, natron. 

3 Omit \tftava>Tbs . . . (ir/zici (11. 31, 32) [* Frankincense and bodies of 
that kind give off vapour in the same sense in which wood does ]. 
The sentence is quite irrelevant to the context and may have been 
absent from Alexander s text. 

4 Alexander s paraphrase ravrn & for TOITWV 8e rd (1. 3) suggests that 
the true reading may be TOVTOJV fi exaora or TOI TCOI/ fie ra el fif/, and the 
varieties of these are determined by the aforesaid qualities . 


by refrigeration. So again in natron, salt, and those kinds of 
stones that are not formed by refrigeration and cannot be 
melted. Blood, on the other hand, and semen 1 are made 
20 up of earth and water and air. If the blood contains fibres, 
earth preponderates in it : consequently it solidifies by 
refrigeration and is melted by liquids ; if not, it is of water 
and therefore does not solidify. Semen solidifies by 
refrigeration, its moisture leaving it together with its heat. 

We must investigate in the light of the results we have I 
arrived at what solid or liquid bodies are hot and what 

25 Bodies consisting of water are commonly cold, unless 
(like lye. urine, wine) they contain foreign heat. Bodies 
consisting of earth, on the other hand, are commonly hot 
because heat was active in forming them : for instance 
lime and ashes. 

We must recognize that cold is in a sense the matter of 
bodies. For the dry and the moist are matter (being 

30 passive) and earth and water are the elements that primarily 
embody them, and they are characterized by cold. Con- 
sequently cold must predominate in every body that consists 
of one or other of the elements simply, unless such a body 
contains foreign heat as water does when it boils or when it 
has been strained through ashes. This latter, too, has 
acquired heat from the ashes, for everything that has been 
5 burnt contains more or less heat. This explains the 
generation of animals in putrefying bodies : the putrefying 
bod> contains the heat which destroyed its proper heat. 2 

Bodies made up of earth and water are hot, for most of 
them derive their existence from concoction and heat, 
though some, like the waste products of the body, 3 are the 
products of putrefaction. Thus blood, semen, marrow, fig- 
juice, and all things of the kind are hot as long as they are 

10 in their natural state, but when they perish and fall away 
from that state they are so no longer. For what is left of 
them is their matter and that is earth and water. 4 Hence 

1 Cp. De Gen. An. 735*29 sqq. 

2 Cp. 379 a 3~ b 8. 3 Cp. De Gen. An. 724^27 and Platt s note. 
4 Read *m for fj in 1. 12 with FX Al. 

BOOK IV. ii 3 8g b 

both views are held about them, some people maintaining 
them to be cold and others to be warm ; for they are 
observed to be hot when they are in their natural state, but 
to solidify * when they have fallen away from it. That, then, 15 
is the case of mixed bodies. However, the distinction we 
laid down holds good : if its matter is predominantly water 
a body is cold (water being the complete opposite of fire), 
but if earth or air it tends to be warm. 

It sometimes happens that the coldest bodies can be 
raised to the highest temperature by foreign heat ; for the 
most solid and the hardest bodies are coldest when deprived 20 
of heat and most burning after exposure to fire : thus water 
is more burning than smoke 2 and stone than water. 

12 Having explained all this we must describe the nature of 
flesh, bone, and the other homogeneous bodies severally. 

Our account of the formation of the homogeneous bodies 
has given us the elements out of which they are compounded 
and the classes into which they fall, and has made it clear 25 
to which class each of those bodies belongs. The homo 
geneous bodies are made up of the elements, and all the 
works of nature in turn of the homogeneous bodies as 
matter. All the homogeneous bodies consist of the elements 
described, 3 as matter, but their essential nature is determined 
by their definition. This fact is always clearer in the case of 
the later products, of those, in fact, that are instruments, as 30 
it were, and have an end : it is clearer, for instance, that 
a dead man is a man only in name. And so the hand of 
a dead man, too, will in the same way be a hand in name 
only, just as stone flutes might still be called 4 flutes: for 390 
these members, too, are instruments of a kind. But in the 
case of flesh and bone the fact is not so clear to see, and in 
that of fire and water 5 even less. For the end is least ob 
vious there where matter predominates most. If you take 
the extremes, matter is pure matter and the essence is pure 5 
definition ; but the bodies intermediate between the two are 

1 Cp. a 19. 2 i. e. burning smoke = flame. 

3 i. e. earth and water. 

4 Read Xt^Otirjtrav (n^) in 1. i with Thurot. 

5 Omit yr]s in 1. 3 with JFHN and probably Al. 


matter or definition in proportion as they are near to 
either. 1 For each of those elements has an end and is not 
water or fire in any and every condition of itself, just as 
flesh is not flesh nor viscera viscera, and the same is true 

10 in a higher degree with face and hand. What a thing is is 
always determined by its function : a thing really is itself 
when it can perform its function ; an eye, for instance, when 
it can see. When a thing cannot do so it is that thing 
only in name, like a dead eye or one made of stone, just as 
a wooden saw is no more a saw than one in a picture. 2 The 
same, then, is true of flesh, except that its function is less 

15 clear than that of the tongue. So, too, with fire; but its 
function is perhaps even harder to specify by physical 
inquiry 3 than that of flesh. The parts of plants, and 
inanimate bodies like copper and silver, are in the same 
case. They all are what they are in virtue of a certain 
power of action or passion just like flesh and sinew. But 

20 we cannot state their form accurately, and so it is not easy 
to tell when they are really there and when they are not 
unless the body is thoroughly corrupted and its shape only 
remains. So ancient corpses suddenly become 4 ashes in 
3QO b the grave and very old fruit preserves its shape only but not 
its taste : so, too, with the solids that form from milk. 

Now heat and cold and the motions they set up 5 as the 
bodies are solidified by the hot and the cold are sufficient to 
5 form all such parts as are the homogeneous bodies, flesh, 
bone, hair, sinew, and the rest. For they are all of them 
differentiated by the various qualities enumerated above, 
tension, tractility, comminuibility, hardness, softness, and 
the rest of them : all of which are derived from the hot and 
the cold and the mixture of their motions. But no one 
would go as far as to consider them sufficient in the case of 

1 And therefore the form, though it is there, is hard to see in those 
bodies which are near to matter, like the elements. 

2 Read dXX ?} <uy 77 fiKwv in 1. 13 with E. 

3 <j)v<riKo>s,\. 16, of which there is no trace in Al., should perhaps be 

4 Read olov in 1. 22 with JFHN Al. and omit u with the MSS. and Al. 

5 Read ra is iVo TOVTUV in 1. 3 with JFHN (rait ano TOVTWV Al. para 

6 Read av en 86<i f (1. 10) with JFN Al. (H too supports m). 

BOOK IV. 12 390 b 

the non-homogeneous parts (like the head, the hand, or the 10 
foot) which these homogeneous parts go to make up. Cold 
and heat and their motion 1 would be admitted to account 
for the formation of copper or silver, but not for that of a 
saw, a bowl, or a box. So here, save that in the examples 
given the cause is art, but in the non-homogeneous bodies 
nature or some other cause. 

Since, then, we know to what element each of the homo 
geneous bodies belongs, we must now find the definition of 15 
each of them, the answer, that is, to the question, * what is 
flesh, semen, and the rest ? For we know the cause of a 
thing and its definition when we know the material or the 
formal or, better, both the material and the formal con 
ditions of its generation and destruction, and the efficient 
cause of it. 2 

After the homogeneous bodies have been explained we 
must consider the non-homogeneous too, and lastly the 20 
bodies made up of these, such as man, plants, and the rest. 

1 Read ^v^por^y <al tfep/iorr/y Kai KIVTJO-IS with E 2 JHN Al. Bag. (sup 
ported by F). 
8 Cp. De Gen. et Corr. 335* 24 sqq, 


3 8a ~ 9 b = 33 8a 39 

Achaea 43 b 2, 66*26, 68 b 6. 

Achelous 5o b i5, 52*35. 

Aedepsus 66 a 29. 

Aegean 54 a 14, 20. 

Aegon 5o b ii. 

Aegospotami 44 b 32. 

Aeolian islands 67*3. 

Aeschylus 42 b 36, 43 a 27. 

Aesop 56 b ii. 

Air, affections common to air and 
water 38 b 24; nearest to fire 
39* 1 8 ; position of air and fire 
relatively to the celestial sphere 
a 33-4 1*36 ; condensed by cold 
41 b 36, 42 a 29 ; acts as a mirror 
42 b 6, 73 b 8, 74*2; continuous 
with the dry exhalation 44* 1 1 ; 
its outermost part potentially 
fire 45 b 32; its constitution a 
condition of the appearance of 
haloes 46*5; drier in summer, 
moist in spring 48 b 27 ; thought 
to become wind, cloud, or water 
according to its state 49 a i6, 
60*27; the sphere of air 54 b 24; 
vaporous air 64 b 27; full of cold 
vapour 6/ a 34 ; condensations 
of 73 a 28, &c. ; in the clouds 
b 2o; in South and in North 
77 h 26 ; contained in oil 84 a 16 ; 
preponderates in all wood but 
ebony b 17. 

Alum 59 b 12. 

Amber 88 b 18-20, 25, 89 a 13. 

Ammon, country of 52 b 32. 

Anaxagoras 39 b 22, 42 b 27, 45* 25, 
48 b i2, 65*17, 19, 69 b i4. 

Anaximenes 65* 18, b 6. 

Aparctias 63 b 14, 29, 31, 64 a 14, 
b 4, 21, 22, 29,65*2, ;f. 

Apeliotes 63 b 13, 64 a i5f., b 19, 
65* 10. 

Arabia 49 a 5. 

Araxes 50*24. 

Arcadia 51*3, 88 b 6. 

Argestes63 b 24, 29, 64* 18, b 5, 20, 
23, 30, 65 a 3, 8. 

Argos 52 a 9. 

Ashes 87 b 14, 89* 28, b 2 f., 9o a 23. 

Asia 50* 18, 53*9. 
Asteius 43 b 19. 

Autumn 4S a I, b 27, 28, 58 b 4, 
65 a 2, 66 b 2. 

Bactrus 5o :l 23. 

Bark85 a 9, 88 a 19, 89 a 13. 

Bearded comet 44* 23. 

Bellowing 3 of earth 68 a 25. 

Bending 85 a 6, 13, b 26 86*9. 

Bird winds 62 a 23. 

Birdlime 85 b 5, 86 b 14. 

Blood 84*16, 25, 31, 89*19, 20. 

b 9, 9o b 1 6. 
Boiling 7Q b i2, 8o b i3, 34, 8i a 9, 

12, 22, b 3, 7, 14,21. 
Boiling, imperfect 79*2, b 14, 8l* 

12, 22, b 9, 14. 
Bone 79*7, 85*8, 87*18, b i, 

88 a 17, 89* 12, b 24, 90*2, b 5. 
Boreas 61*22, 64 b 26. 
Bosporus 53 a 7, 72* 15. 
Breaking 85* 14, 86* 9-17. 
Broiling 79 b 13, 81*23, b 3, 14, 

16, 21. 
Broiling, imperfect 79 b l4, 8i b 16. 

Caecias 63 b 17, 30, 64* 15, b I, 12, 
14, 18, 24, 25. 

Canopus 5i b 33- 

Carbuncle 87 " 18. 

Caspian 54*3. 

Caucasus 50*26, 28, 51*8. 

Cause, originating principle of all 
motion the first 39 a 23. 

Celtice 5o b 2. 

Chaonia 59*25. 

Charybdis 56 b 13. 

Chasms 42*35, b i4, 17, 52 b 6. 

Cheese 84 a 22, 24, 30, 88 b 12. 

Chios 42 b 36. 

Choaspes 50*24. 

Chremetes 5o b 12. 

Cinnabar 78 a 26. 

Cleidemus 7o a II. 

Clouds, why not formed in upper 
air 40 a 25, b 29; when they 
gather * 30 ; = air condensing 
into water 46 32 ; mist = barren 


cloud 46 b 35; frozen cloud = 
snow 47 b 23; clouds contain 
much heat ib. 26 ; collect on 
either side of sun s course 6i a 9 ; 
blown away by north winds 
64 b S; lightning ejected when 
clouds contract 64 b 32 ; their 
density highest at their upper 
limit 69*16; densest on side 
where heat escapes 7i a I ; rain 
bow is purest when cloud 
blackest 75* 9. 

Coal 87 b iS. 

Cold, air condensed by 4i b 36; 
more cold needed to freeze 
vapour than water 47*25; three 
bodies condensed by b 12 ; con 
centrated within by external heat 
48 b 15 ; condenses vaporous air 
into water 49 b 23 ; condenses 
vapour into water 6o a I ; towards 
sunrise, reason of 67 a 26 ; pre 
vails over the dry evaporation 
71*6 ; snow and northerly rain 
occur when cold prevails a 8; 
adverse to putrefaction 79 a 26 ; 
= lack of heat 8o a 7 ; natural 
cold perfects the matter it 
determines * 19 ; iron solidified 
by 84 b 14 ; sweet wine not solidi 
fied by 87 b 10 ; the matter of 
bodies 89 a 29 ; earth and water 
characterized by a 3 1 . 

Coldness of north wind concen 
trates heat by recoil 47 b 5 ; of 
mountains 52 b 7. 

Colour without shape, reflection of 
73 b 24 ; homogeneous bodies 
differentiated by 88 a 13. 

Combustible 84* 1 6, 85** 1 8, 87* 1 7- - 
22, b i 3 , 18. 

Comets 42 b 25 45 a io, 45 b i2, 

3546 a 3 M, * I, 8, 13- 
Comminution 85 a 14, S6 a 9-17, 

87 a i, 9o b 7. 

Compressible 85 a 17, 87 a 15. 
Concoction 79* 12 8o a 10, 8o a 

ii f., 22, b i 3 , 1 6, 8i a 9, 23, b 7, 

10, 15, 20. 

Cooling, things dried by 82 b 18. 
Copper 77 b 21, 78 a 28, b 1,85*33, 

b i 3 f, 86* 17, 22, b i8, 87 b 2 5 , 

28, 88 a i4, 89 a 7, 9o a i7, b u. 
Coraxi 5l a n. 
Corinth 45* 4. 

Crown (constellation) 62 b 10. 
Curd 8i a 7. 

Cutting 8s a l7, 86 b 30, 87*3-11. 

Darius 52 b 28. 

Deluge 52 a 33, cf. 68 b 5, 12. 

Democritus 42 b 27, 43 b 25, 45*25, 

56 b 10, 65 a 1 8, b i. 
Deucalion 52 a 32. 
Dew 47 a i6, 18, 22, 36, b 17, 20, 

3i,49 a 9> 78 a 3i- 
Diagram 75 b 18. 
Dodona 52 a 35. 

Dolphin (constellation) 45 b 22. 
Dough 86 b l4. 
Dross83 b i. 
Drought 44 b 2o, 6o b 5, 9, 6l b 9, 

65 b 9 , 10, 66 b 3, ;f., 68 b 16. 
Dyes 75*23, cf. 28. 

Earth, its kinds and parts 

occupies the lowest place 39 a 1 7 ; 
rays reflected from 40* 28 ; and 
water, the heaviest and coldest 
elements b 20 ; dry exhalation 
from b 26, 4i b 10, 6i a 30, 62 a 5, 
69 a 3 ; smaller than sun 45 b 2 ; 
shadow of earth does not reach 
stars b 9 ; moist exhalation from 
47 b 27, 69* 3 ; small particles of, 
swim on water 48 a 8 ; lower 
parts of, cold in warm weather, 
warm in frost b 3 ; thought to 
sweat water out fjo a i, 53 b n, 
57 a 24, b 18 ; cavities in 5o b 36 ; 
the same parts of, not always 
moist or dry 5i a 19, 33, 53 a 25 ; 
interior of, grows and decays 
51*27; vital process of b 8; 
small in comparison with uni 
verse 52 a 27; thought to have 
been at first surrounded by 
moisture 53 b 6; when heated 
assumes flavours 59 b 10 ; fire in 
6o a 5, 67*9; heat in 60*16; 
inhabited 62 b 13, 26, 63 a I, 
64 a 7, 65* 30 ; essentially dry 
65 b 24, 82 a 3, b 3 ; bellowing 
of 68 a 25 ; two kinds of bodies in 
78* 20 ; bodies made up of earth 
and water 83 a 13, 26, b 1 8, 84*3, 
17, b 3o; soluble 83 b 9; stones 
formed by burnt earth b 1 1 ; 
homogeneous bodies (mainly) 
made of earth 88*25. 

Earthquakes, causes of 38 b 26, 

Ebony 84 b I7f. 

Eclipse 67 b 2o, 25-27, 30 f. 


Eddy 70^22, 28, 71* n. 
Egypt 5i b 2S, 34. 
Egyptians 43 b 10, 28, 52 b 2i. 
Element 38 a 22, b 2i, 39 b 5, 17, 

, 27. 

5, b n, 

55 b i,78 b iof., 
Empedocles 57 a 26, 6g b 12, 8i b 

32, 8 7 b 4- 
Ephesus 7i a 31. 
Equator 77* 18. 
Equinox 63 a 34 f., b 12, 14, 64* 17, 

7i b 3o, 77*12, 14. 
Erytheia 59=* 28. 
Etesiae 6i b 24, 35, 62 a 12, 19, 23, 

24, 30, 65*15, 65*6. 
Ether 39 b 2i, 24, 27, 65*19, 6g b 

14, 20. 

Ethiopia 49 a 5, 62 b 2i. 

Ethiopian 5o b 11. 

Euboea 66 a 27. 

Eucles 43 b 4. 

Euripus 66*23. 

Euronotus 63 b 22. 

Europe 5o b 3. 

Eurus 63 b 2i, 64 a i7, b 3, 20, 24, 
26, cf. 63* 7. 

Euxine 5o b 3, 54*17. 

Evaporation (exhalation), dry, 
from the earth 4O b 26, 44* 10, 
58*19, 34, 69*26, 33, 7S a 2i ; 
ignited by motion 4i b 35, 42* 
17; of right consistency 44* 20; 
moist evaporation dissolved by 
hot exhalation b 23 ; e. of water 
= vapour 46 b 32 ; south wind 
allows it to accumulate 47 b 
10; sun s heat wastes the heat 
in e. 6i b 15 ; quenched by cold 
b 25 ; generally moves con 
tinuously 66*6 ; vaporous 78* 
26 ; e. of two kinds 4i b 7, 57 b 24, 

58*21,60*8, 78*18, 84 b 33- 
Excreta So* I, b 5- 

Fat 87 b 6, 88*7. 

Fibres 84* 28, 88* 17, 89* 20 f. 

Fire occupies the highest place 
39*16; ether identified by 
Anaxagoras with fire b 22 ; the 
heavens thought to be fire b 30, 
40* i ; what we commonly call 
fire 40 b 22 ; the dry exhalation 
potentially like fire b 29, cf. 
41*7 ; fire surrounding the air 
41*30; warm and dry element 
b 14 ; outermost part of air 
potentially fire 45 b 32 ; lives as 

long as it is fed 55*4 ; lightning 
thought to be fire shining 
through cloud 70* 23 ; fire inten 
sified by added fire 75* 20 ; the 
other elements matter relatively 
to fire 79 a 16 ; proper fire b 3 ; 
external fire 8i b 18 ; pores such 
as to admit fire 87* 19. 

Fire-winds 39*4, 69* 1 1, 7 i a i6, b 1 5. 

Fissile 85* 16, 86 b 2587* 1 1. 

Flame = ebullition of dry ex 
halation 4i b 21 ; through smoke 
creates various colours 42 b 1 9 ; 
a becoming, involving constant 
interchange of moist and dry 
55*9; fire becomes flame only 
when wind accompanies it 
66* 2 ; = burning smoke or 
dry exhalation 88*2. 

Flavour 54 b I, 

56*13, 57*9, 1 6, 
12, 20, 
78 b i, 8o b 2, 32, 87 b 12, 88* 12. 

58*5, n, b i9>22, 59 b 9, 

jO ft 

Flesh 79*7, 85*8, 86 b 8, 88 
, 14, 16,19, b s 


Flutes 89 b 32. 

* Fore-runners 6i b 24. 

Form, nature as 79 b 25. 

Fossiles 78*20, 22, 24. 

Frankincense 87 b 26, 30, 88*3, 

b 2o, 31, 89*14. 
Friable 85*17, 87*1 
Frost 43 b i9, 48 b 4, 6i b 26, 66 b 5, 

Fruit 8o a u, 14, 16, 28, 85 b 19, 

89* 15, 90*23. 
Fumes 85* 18, 87* 23 b 13, b 21, 

3 i,88 :l 3, 89*17. 

Glass 89* 8. 

Goats 4i b 3, 28, 31. 

Gold 48* 9, 78*28, b i, 4, 8o b 29, 

8 4 b 32, 88*14, 89*7- 
Graeci 52 * 2. 
Greece 51*7, 52*9. 
Greek world 5o b 15, 52*33. 
Gum 88 b 20. 

| Hail 47 b 14, 28, 31 f., 34-49 a ", 

69 b 32, 88 b i2. 
Hair 86 b i4, 87 b l, 4, 88*17, 89* 

12, 9o b 5. 
Haloes 44 b 2, 6, 13, 18, 46* 5, 7l b 

1873*31, 73 b 34, 74 a 10, 15, 

77 b 34- 
Hard 82* 10 f., 15, 18, 20, 22, 25, 

83*23, b 7, 86*22 f., b 33, 87*4, 



Heat why stars impart heat to 
earth 40" 21 ; derived from sun 
41*12; sun causes terrestrial 
41*19; tends upwards 42*15, 
cf. 4i a 5,69 a 25 ; raises moisture 
47 a 8 ; thrusts clouds up from 
earth 48 a 20 ; everything that 
has been exposed to fire has 
heat potentially 58 b 7, 89 b 4; 
of earth 62 a 6, cf. 6o a i6; and 
cold, winds distinguished by 
64 a 22 ; of sun, not the cause 
of thunder and lightning 69 b 25 ; 
heat the cause of spontaneous 
generation 79 b 7 ; matter de 
termined by connatural heat 
b 34; various modes in which 
natural heat perfects matter 
8o a i9; dry heat or cold the 
agent of solidification 82 b 33, 
84 b is; bodies solidified by 
cold, melted by heat 85 a 3i; 
burning heat produces vapour 
fromliquid87 a 25,cf.3o; foreign 
heat 89 a 26, b I, 19 ; heat which 
destroys the proper heat of a 
body b 6; most compounds of 
earth and water derive their 
existence from concoction and 
heat b 7. 

Hebrus so b 17. 

Hellas 52 a 34. 

Hellenes 52 b 3. 

Hellespont 66 a 26. 

Hellespontias 64 b 19. 

Hephaestus 69* 32. 

Heracleia 67 a I. 

Heracles 59 a 28; pillars of 54 a 12, 

62 b 2I, 28. 

Heraclitus 55 a 14. 

Hercynian Mountains 5O b 5. 

Hestia 69 a 32. 

Hiera 67 a 2. 

Hippocrates 42 b 36, 43 a 28, 44 b i5- 

Hissing 6g }) 17, 7o a 8f. 

Hoarfrost 47 a 16 b 33, 49* 10, 

78*31, 88 b l2. 
Homer 5l b 35- 
Homogeneous bodies 84 b 30, 85 a 

10, 88 a ii, 13, 25, 89 b 24f., 27, 

90% 15. 

Honey 83*5, 84 a i5,85 b 2,88 b io,23. 
Horizon 43 a 18, 32, b 16, 63* 27, 

65*29, 75 b 27, 76 b 22, 29, 32, 

77 a 8. 
Horn 83 a 32, 84 b i, 85 b ii, 88 b 3i, 

8 a ii. 

Hurricane 65* I, 3, 66 b 33, 69* 19, 

7o b 8 -7i b i7. 
Hyrcanian sea 54*3. 

Ice 47 b 36, 48 a 32, b 34, 36, 49 a 2, 
62 a 5, 85 a 3 2, b 7, 86* 10, 87*19, 
22, 88 b ii, 16. 

Impact 86 b I. 

Impressing 85* 15, 86 a 17-29, 

b 22f., 87 a l. 

Inachus 5o b 16. 

Inconcoction (indigestion) 79 b 13, 

8o a 6, 9, 8i a i2, 13, b 2o, cf. 57 b 

9, 79 a 2, 80*28, 8i b 9. 
India 62 b 2i, 28. 
Indus 5o a 25. 
Inflammable 87 b 18-32. 
Iron 78 a 28, 83 a 3i f., b 4, 84 b 14, 

8 5 b ii, 86 b io, 33, 88 a i 4 , b 3i, 

Istrus 5o b 2f., 9, 
Italy 67 a 7. 

Jupiter 43 b 3- 

Land, relation of, to sea 5 i a 21. 
Lead 49 a 2, 85 a 32, 89 a 8. 
Leguminous plants 89 a 15. 
Libya so 1 ii, 52 b 32, S^ 3, 63*5. 
Light 42 b 6, 15, 45 a 26, 28, 31, 

h 29, 46 a 24, 67 b 22, 74 a 27. 
Lightning 64 b 30, 32, 69 a 10 70* 

33 70 b 7, 7i b i4- 
Liguria 5i a 16, 68 b 32. 
Lime 83 b 8, 89 a 28. 
Lipara 67* 6. 

Lips 63 b 19, 23, 64 a 16, b 2, 18, 25. 
Lye57 b i,58 b 9, 59 b 7, 12, 78 a 25, 

Lyncus 59 b 17. 

Maeotis 50*25, 53*1, 54*13, 17, 

20, 62 b 22. 

Malleable 78*27, 85* 16, b 10, 86 b 

Marrow 89 b 10. 

Material cause 39* 28, 42* 28. 

Matter, ratio of active powers 
to 78^33; the other elements 
matter relatively to fire 79 a 16; 
concoction ensues when matter 
is mastered b 32 ; the passive 
qualities the natural matter of 
a thing 8o a 8 ; earth and water 
the matter of all bodies 82 a 7 ; 
the dry and the moist are matter 
89 a 30 ; the end least obvious 
where matter predominates 


most 90* 3 ; pure matter a 5 ; 
knowledge of cause = know 
ledge of matter or form or both, 
and of efficient cause b 17. 
Melting 8i b 28, 82 b 29, 83*26 
b i7, 4 b 14-23,85* 12, 27 b I, 

b 12-26, 87 b 25 f., 31, 88 b 32f., 
89*9, 19,21. 

Memphis 52*1. 

Mercury 42 b 33- 

Meses 63 b 3o, 34, 64*15, b 2i, 31. 

Metals 78*21. 

Meteorologists 54* 29. 

Meteorology 38* 26. 

Milk 8o b 8, 32, 8i a 7, 82 b i2, 83* 
22, 84* 16, 24, 30, 88* 31, 9o b 2. 

Milky way 38 b 22, 39*34, 42 b 25, 
45*9, II 46 b i5. 

Mill-stone 83 b 7, 12. 

Mirror which reflects colour, not 
shape 42 b 12, 72*33 ; air acting 
as 73 b 8 ; particle of rain a better 
mirror than mist b 1 5 ; cloud 
acting as b 22. 

Mist46 b 33, 35>6i*28,67 b i7,73* 
I, b !2, 17, 74*7, 1 8, 77 b i9. 

Moisture in and on the earth 4i b 
9 ; attracted by comet 43* 3 ; 
surrounding earth 46 b 24, 57* 7 ; 
the same places not always 
moist 52 b 1 8 ; drawn up by sun 
57 b 2o; in something dry, the 
condition of evaporation 62 a 10 ; 
of air 74* 24 ; acquires cer 
tain properties or magnitude 
through being heated 79" 27, cf. 
8o b 27 ; concoction ensues when 
moisture is mastered 79 b 32 ; 
undetermined 80* 29 ; existing 
separately 82 b 19 ; aqueous 85" 
I ; weaker than fire 87* 20. 

Molon 43 b 5. 

Moon, eclipses of 67 b 2O. 

Moulding 85* 15, 86*27, 29. 

Mountains 41*1, 47*29, 50*3-5, 
15, 19, 20, 29, b i, 5, 11, 14,21, 
27, 52 b io, 56 14. 

Mud 83*29, b 9, 85*31, 86 b 25. 

Must 79 b 3o, 8o b 32, 84*5, 85 b 3. 

Mycenae 52*9, n. 

Myrrh 88 b 20, 89* 13. 

Natron 83 b 12, 19, 84* 18, 34, 85* 
31, b 9, 1 6, 23, 88 b i3, 89*18. 

Nature as formal cause 79 b 25 ; art 
imitates nature 8 i b 6 ; 3Cart9o b 

Nessus 5o b 16. 

Nicomachus 45* 2. 

Night the shadow of the earth 

45 b 7- 

Nile 5o b 14, 5i b 30, 53* 16, 56 a 28. 
Nyses 5o b i2. 

Ocean 47 a 6. 

Ochre 78 a 23. 

Oil 81* 8, 82 b 16, 83 b i4, 21, 28, 

84*16, 85 b 4 , 87 b 7, 10, 22, 88* 

5, 9,32, * io. 
Orion 43 b 24, 6i b 23, 30. 

Palestine 59 a 17. 

Parnassus 5o a 19. 

Peloponnesus 5i a 2. 

Phaedo 55 b 32. 

Phaethon 45* 15. 

Phasis 5o a 28. 

Phlegm 8o a 2i, 84*32, 86 b 16. 

Phlegraean plain 68 b 3l. 

Phoenicias 64*4, 17. 

Pillars of Heracles 5o b 3, 54*3, 

12, 22, 62 b 2I, 28. 

Pindus 5o b 1 5. 

Pitch 82 b 1 6, 85 b 5, 87 b 22, 88* 4, 9. 

Planet 42 b 28, 31, 43 b 29, 44 a 3 6 , 

45 b 28,46 a 2, 12. 
Plants 39*7, 5i a 27, 78 b 3i, 8 4 b 

31, 88 a i6, 19, 90*17, b 2i. 
Pole 62*33, "4, 31, 63*8, 76 a i8, 

b 8, 31,77*1, io. 
Pontus 47 a 36, b 4, 48 b 34, 5l a i2, 

54 a i4, 20, 67*1. 
Pore 8i b i, 3, 85 a 29, b 2O, 24, 25, 

86*15, b 2, 4-6,9,87*2, 19,21. 
Potter s clay, pottery 83 a 2i, 24, 

b u, 20, 84*34, b 2, 19, 85*30, 

b 9, 28, 86 a n, 18,23, b 26,88 b 

12, 18. 

Pressure 86 a 19, 33, b S. 
Putrefaction 79 a 3 b 9, 89 b 8. 
Pyrene 5o b i. 
Pyrimachus 83 b 5. 
Pythagoreans 42 b 3O, 45 a 14. 

Rain 46 b 35, 47 a 12, b 17 f., 31, 49 a 

4,9, 32, 


28, 6o b 6, 8, 27-29, 6i b io f., 65* 

22, b io,24,66 b 3, 9, 68 b i7, 7o b 

12, 16, 72 b 24. 
Rainbow 7i b i8, 26, 32, 72 a 9, 21, 

73 a 2,3277*28. 
Rawness 79 b 13, 80*27, 30 f., b 4, 

12, 8l b 2I. 

Realgar 78* 23. 


Recoil 48 b 2, 49* 8. 

Red Sea 52 b 23, 54*2. 

Reflection by air 42 b 6 ; comet s 
tail not due to 43* 26 ; colour of 
halo due to 44 b 7 ; r. of sight to 
sun 45 b io, 20, 72 b i5, 73 b 33, 
cf. ib. 21 ; haloes, rainbows, c., 
are reflections 46* 5, 72* 18, 73 b 
31, 74*8; theory of 70*16; 
lightning believed to be a r. ib. 
23; diminishes vision 74 b 21 ; 
weakened by distance 75* 34 ; 
causes sun s true colour to 
appear in mock-sun 77 b 18. 

Refrigeration, things solidified 
by 88 b 1 3 ; amber and tears 
formed by b 19, 89* 17 ; blood 
solidifies by 89* 20. 

Rennet 84*21, 89 b 10. 

Rheum 79 b 32. 

Rhipae 5o b 7. 

Rhodamis 51* 16, 18. 

Rhodope 5o b i8. 

Ripening 79 b 1 2, 80*11-13, 16, 21, 
26, 28, 30, b 4, II, 8i b 2o. 

Rivers, origin of 49 b 2 51*18; 
their effect on land surface 51* 
20; Plato s theory of 5$ b 32 

Rods 70* 13, 7i b i9, 72* ii, 74 a 

17, 77 a 2978 a i4. 
Ruddle 78* 23. 

Salt 59*13,29, 32, b 4, 83 b 13, 20, 
84 a i8, 85*31, b 9, I6,88 b i3, 15, 


, 542, 

4, 57 

5, 1 6, b 7, 22, 58*4, 59*5. 

Sardinian sea 54*21. 

Sciron 63 b 25. 

Scombrus 5o b 17. 

Scythia 5o b 7, 59 b 18, 62 b 22. 

Sea, advance and retreat of 53* 
22 f. ; thought to be the original 
of all water 54 b 3 ; the end, not 
the source, of water 56*35 ; cools 
evaporations 68 b 33. 

Sellus 52 b 2. 

Semen 89* 19, 22, b 10, 9o b 16. 

Serum 84*32, 89* 10. 

Sesostris 52 b 26. 

Shooting-stars 41* 33, b 2, 28, 34, 
42*7, 27, b 4,21, 44 a 15, 28,46 b 


Sicania 59 b 15. 
Sicilian sea 54*21. 
Sicily 59 b 15, 66*26. 

Silver 84 b 32, 8s b 4, 88* 14, 89*7, 
90*17, b 12. 

Silver Mountain 5o b 14. 

Sinew 85*8, 86 b 14, 88* 17, 89* 12, 
90*19, b 5. 

Sipylus 68 b 3l. 

Skin 88*17. 

Smoke, stars look crimsonthrough 
42 b 10, cf. 1 9 ; green wood gives 
most 6 1* 19; is exhalation and 
burns 71*33 ; = fumes of woody 
body 87* 32, 88* 2 ; flame is 
burning smoke 88* 2. 

Snow 47 b 13, 16, 23, 30, 48*3, 22, 
49 a 9, 59 a 33, 62*18, 64*8, 69 b 

31, 71*8, 88 b n. 
Soft 82*11-21. 

Softening by heat 84 b 1, 16, 85* 13, 

b 6-i2, 88 b 30, 89*17. 
Softening by water 85* 13, b i2- 

Solidification 82*25, b 3i, 84 b 23, 

85* 12, 20 b 5, 88*28. 
Solstice, summer 43*15, b i, 62* 

12, 31 ; winter 43 b 6, 62* 22 ; 

solstices thought to be caused 

by air 55*25. 
Soluble 83 b io, 13, 84 a 34. 
Soot 74*24, 26, 87 b 6, 88*4. 
Sponge 50*7, 86*28, b 5, 7, 17. 
Spring 47 b 37, 48 b 26, 28, 65* 2, 

66 b 2. 
Springs 50*5, b 28, 30, 34, 5i b i, 

53 a 35, b i7, 20, 22, 27, 31,54*5, 

32, 5 5 b 35, 56*29, 59*25, 30, b 5, 
8, 17, 60*33; hot 66*28. 

Squeezing 8 5* 1 5, 86* 29 b 24, 87* 


Stalactites 88 b 26, 89*14. 
Stars, why they heat the earth 40* 

21 ; heat of * 28 ; at rising and 

setting look crimson 42" 10; 

fixed 43 b 9, 29, 44* 36, 46* 2 ; 

in milky way 45 b 19, 46* 10, 19, 

25, 27 ; milky way due to motion 

of 46* 26. 
Stone (meteorite) 44 32 ; fall of 

stones after earthquake 68 b 28 ; 

insoluble stones 89* 1 8. 
Straightening 85 b 27, 66* 7 f. 
Strymon 5o b 16. 
Sulphur 78*23. 
Summer 48* 18, b 26, 28, 49* 5, b 8, 

61*13, b 32, 66 b 4, 79 a 29J late 

summer 48* I, b 3o. 
Sun, heat derived from 41*13; 

sun s motion enough to account 


for terrestrial warmth ib. 20; 
hottest of the stars ib. 35; 
tropics dried up by 43* 9, 63* 14 ; 
draws up moisture on surface of 
earth 6o a 7 ; regions unvisited 
by 6i a 7 ; sun at full force shuts 
evaporation into earth 66* 16 ; 
night calmer than day owing to 
absence of 66 a 1 7 ; mock sun 7 1 b 
19, ;2 10, 16, 77 a 29 f. 78 a 14. 

Tanais 5o a 24, 53* 16. 

Tartarus 56*1, 18. 

Tartessus 5o b 2. 

Tears 79 b 3i. 

Tears 8S b i9, 89^4. 

Thebes 5i b 34- 

Theogonies 53 a 35. 

Thickening 83 a n. 

Thrascias 63 b 29, 64* I, 14, b 4, 22, 

29, 6s a 3, 7. 
Thunder 69*10, 29, b i, 3, 8, 17, 

19, 29,70*22,24, 27, 31,33, b 7, 

7i b u, 14. 
Thunderbolt 39 a 3, 42 a 13, 69* II, 

19,71*19, b 8, 15- 
Tin 88 a i4, 8g a 8. 
Torches 41 b 3, 28, 32, 42 b 3, 16, 

44 a 26. 
Tractile 85* 16, b 10, 86 b 11-18, 

87 a ii. 

Tractility 9O b 7. 
Trenches 42* 36. 
Trojan wars 52* lo. 
Tropics 43 a 9, 14, 45*6, 46 a 14, 1 8, 

62 b 2. 

Twins (constellation) 43 b 3i. 
Tyrrhenic sea 54 a 21. 

Umbria 59*35. 

Urine 57 b 2, 8o a I, b 5, 82 b 13, 84 a 
13, 89*10, 27, cf. 66 b 19. 

Vapour, what surrounds the earth 
40*34; = water dissolved l) 3, 
46 b 32 ; moist and cold 4O b 27 ; 
when cooled becomes water 46 b 
29, 47 b 18, 6o a 2, 84 a 6; flows 
upwards when sun is near 47* 
4 ; when frozen = hoar-frost 
a 1 6, b 24 ; dew and hoar-frost 
due to its not rising high b 28 ; 
south wind carries little 58*31 ; 
Caecias carries much 64 b 29 ; 
combination with dry exhala 
tion causes fine weather 72 b 32 ; 
defined 87*25. 

Vinegar 59 16, 84* 13, 89* 10. 
Viscosity 82 b 14, 16, 83 b 34, 84* 2, 

Water, affections common to air 
and water 38 b 24 ; does not exist 
independently 39 b 9 ; dissolves 
into air 40* 10, 24 ; vapour = 
water dissolved b 3, 46 b 32 ; and 
earth, the heaviest and coldest 
elements 40^ 20 ; vapour poten 
tially like water b 28 ; does not 
freeze on earth as in the clouds 
47 b i i ; flowing X stationary 5 3 b 
18; the water that has been 
carried up comes down again 
55* 26 ; dries more quickly when 
spread out b 25 ; sea = totality of 
river- water 57* 21 ; acid water 
59 b i4; matter which might have 
become water 78* 33 ; alone of 
liquids does not thicken 8o a 34 ; 
ebony does not float in 84 b 17 ; 
water boiled or strained through 
ashes contains foreign heat 89 b 
i ; bodies chiefly consisting of 
water are cold b 16. 

Wax 86*17, 21, b 8, 25,87 b 22, 88* 

Weather, fine (warm) 46 34, 47 a 
22, b i, 2, 5, 72 b l9, 29,33. 

Whey 81* 7, 82 b 13, 84 a 14, 20, 
22f., 89*10. 

Whirlwind 39* 3, 69 a lo, 71* 2 f., 9, 
b !5. 

Wind, causes of 38 b 26 ; originates 
in marshy districts 4o b 36 ; does 
not blow above level of highest 
mountains b 37 ; prevents forma 
tion of dew and hoar-frost 47 a 
27 ; theories of 49* 16 b 2 ; the 
south the wannest wind 58 a 29 ; 
causes of wind 59 b 27 63*20; 
ceases when rain comes on 6o b 
29 ; north and south winds 
predominate 6i a 5, 20 ; both 
checked and stimulated by sun 
b !4; white south winds 62* 
14 ; north wind blows from 
arctic regions a 16 ; ordering of 
winds in southern hemisphere 
b 32 ; north wind like a land 
breeze 63* I ; south wind blows 
from torrid region a 12 ; direc 
tion, number, concomitants, and 
natures of the winds *2i 65* 
13 ; true north wind 63 h 14, 64* 



13 ; north winds overpower 
other winds 64 b 7 ; wind in our 
bodies 66 b i6; premonitory in 
dication of south wind 67* 
13 ; winds before eclipses b 25 ; 
severity of earthquake deter 
mined by quantity of wind 68 :i 
I, b 22 ; breaking up of halo y c ->a, 

a sign of wind 7 2 b 26, 73*24; Year great * 2 -> 

rain in 6o a 2 ; in the north is 

windless 6i b 5. 
Wood consists of earth and air 

8 4 b i5. 
Wool 75* 26, 82 b 12, 8s b 14, 18, 86 a 

28, b 16,25, 8 7 a i8. 

Wine 58 b i9, 82 b i3, 84*4, 13, 7 b 

9, i if., 88 a 33, b 2, 10,89*9,27. 

Winter, great 52*31; why more 

Zephyrus 63 b i2, 64 b 3, 23, 65" 8, 

cf. 63 a 7, 64 a 18. 
Zodiac 43 a 24, 45*20. 46*12. 

Printed in England at the Oxford University Press 











THIS interesting little treatise has no claim to be 
regarded as a genuine work of Aristotle. In his careful 
examination of it (Neue Jahrbiicher, xv (1905), pp. 529-68) 
Wilhelm Capelle has traced most of its doctrines to Posei- 
donius, and comes to the conclusion that it is a popular 
philosophic treatise founded on two works of Poseidonius, 
the MeTtdopoXoytKT) oroi^e/coo-iy an d the Ilepl KOCT^JLOV. 

The treatise is addressed to Alexander, who must either 
be Alexander the Great (in which case the author doubtless 
wished to have his work attributed to Aristotle, and there 
fore addressed it to Aristotle s most distinguished pupil), 
or else some other Alexander must be intended. From 
the fact that he is spoken of in 39i b 6 as fjyefj.ovcoi dpia-ros, 
it has been supposed that Tiberius Claudius Alexander, 
nephew of Philo Judaeus and Procurator of Judaea, and in 
A. D. 67 Prefect of Egypt, is intended. In this case the 
treatise must be dated early in the second half of the first 
century A. D. Capelle, however (1. c. p. 567), dates it in the 
first half of the second century A. D. 

The description of the natural phenomena of the universe 
is the most Aristotelian portion of the work, and many close 
parallels are to be found in the Meteor ologica. It has been 
thought better not to multiply references to the Meteoro- 
logica in this part of the treatise, but a certain number of 
references have been added in other places. 

The text used for this translation is that of Bekker in the 
Berlin edition. A complete account of the literature upon 
the DC Mundo will be found in Capelle s article (1. c. p. 532). 
I have to thank Mr. W. D. Ross, who read the translation 
in manuscript and in proof, and my colleague, Professor 
W.C. Summers, who read the greater part of it in manuscript, 
both of whom made a number of valuable suggestions. 

Dec. 2, 1913. 



i. Introduction. 

2. The elements of the Universe : Ether, Fire and Air. 

3. Earth and Sea. 

4. The natural phenomena. 

5. The position of God in the Universe. 

6. 7. God and His attributes. 


[ MANY a time, Alexander l , has Philosophy seemed to me 39 1 * 
a thing truly divine and supernatural, especially when in 
solitude she soars to the contemplation of things universal 
and strive^ to recognize the truth that is in them, and 
while all others abstain from the pursuit of this truth 
owing to its sublimity and vastness, she has not shrunk 5 
from the task. nor thought herself unworthy of the fairest 
pursuits, but has deemed the knowledge of such things at 
once most natural to herself and most fitting. For seeing 
that it was not possible (as once the foolish Aloadae 2 
attempted) by means of the body to reach the heavenly 
region and leaving the earth behind to spy out that 10 
heavenly country, the soul by means of philosophy, taking 
the intellect as her guide, finding an easy path has tra 
versed the intervening space and fared forth on its pilgrim 
age, and by intelligence comprehended things very far 
removed in space from one another, easily, methinks, 
recognizing those things which have kinship with one 
another, and by the divine eye of the soul apprehending 15 
things divine and interpreting them to mankind. This 
she felt, being desirous, as far as in her lay, freely to give 
to all men a share of her treasures. And so men who 
have laboriously described to us either the nature of a 
single region or the plan of a single city or the dimensions 
of a river or the scenery of a mountain, as some ere now 20 
have done, telling of Ossa or Nysa or the Corycian 
cave 3 or giving us some other limited description, such 
men one should pity for their small-mindedness in admir 
ing ordinary things and making much of some quite 
insignificant spectacle. They are thus affected because they 
have never contemplated what is nobler the Universe 25 
1 See preface. 2 Otus and Ephialtes. 3 Paus. x. 32. 2. 

39i a DE MUNDO 

and the greatest things of the Universe ; for if they 
had really given attention to these things, they would 
3gi b never marvel at anything else, but all else would appear 
insignificant and, compared to the surpassing excellence 
of those other things, of no account. Let us therefore 
treat of all these matters and, as far as possible, inquire 
into their divine nature, and discuss the nature and position 
5 and movement of each of them. And I think that it is 
but fitting that even you, who are the noblest of rulers. 
should pursue the inquiry into the greatest of all subjects 
and in philosophy entertain no trivial" thoughts, and make 
the noblest among men welcome to these only of her gifts. 

The Universe then is a system made up of heaven and a 

10 earth and the elements which are contained in them. But 
the word is also used in another sense of the ordering 
and arrangement of all things, preserved by and through 
God. 1 Of this Universe the centre, which is immovable 
and fixed, is occupied by the life-bearing earth, the home 
and the mother of diverse creatures. The upper portion 

15 of the Universe has fixed bounds on every side, the highest 
part of it being called Heaven, the abode of the gods. 
Heaven is full of divine bodies, which we usually call 
stars, and moves with a continual motion in one orbit, and 
revolves in stately measure with all the heavenly bodies 
unceasingly for ever. The whole heaven and universe being 

30 spherical and moving, as I have said, continually, there 
must of necessity be two points which do not move, exactly 
* opposite to one another (as in the revolving wheel of 
a turner s lathe), points which remain fixed and hold the 
sphere together and round which the whole universe moves. 
The universe therefore revolves in a circle and the points 

25 are called poles. If we imagine a straight line drawn so 

as to join them (the axis, as it is sometimes called), it will 

form the diameter of the Universe, occupying the centre 

3Q2 a f tne earth, with the two poles as its extremities. Of 

1 Reading with W. Capelle, Neue Jahrb. xv (1905), p. 535, \mb 
teal 8ia 6(6v : Bekker s reading, VTTO $eo>j> re K<U 8m tic&v, contradicts the 
pantheistic character of the treatise. R reads dia 0eoV, Q 8t 0eov. 

CHAPTER 2 3Q2 a 

these fixed poles the one is always visible, being at the 
summit of the axis in the northern region of the sky, and 
is called the Arctic Pole l ; the other is always hidden 
beneath the earth to the south and is called the Antarctic 

The substance of the heaven and stars we call Ether, 2 5 
not because it blazes, owing to its fiery nature (as some 
explain the word, mistaking its nature, which is very far 
removed from fire), but because it is in continual motion, 3 
revolving in a circle, being an element other than the four 
indestructible and divine. Of the stars which are con 
tained in it, those called fixed revolve only with the 10 
whole heaven, always occupying the same positions. A 
belt is formed through their midst by the so-called Circle 
of the Zodiac, which passes crosswise through the tropics, 
being divided up into the twelve regions of the Signs of 
the Zodiac. Others, which are called planets , do not 
naturally move with the same velocity as those stars of 
which I have already spoken, nor with the same velocity 15 
as one another, but each in a different course, so that one 
will be nearer the earth, another higher in the heavens. 
Now the number of the fixed stars cannot be ascertained 
by man, although they move in one surface, which is that 
of the whole heaven. But the planets fall into seven 
divisions in seven successive circles, so situated that the 20 
higher is always greater than the lower, and the seven circles 
are successively encompassed by one another and are all 
surrounded by the sphere containing the fixed stars. The 
position nearest to this sphere is occupied by the so-called 
circle of the Shining star , or Cronos; next is that of the 
Beaming star , which also bears the name of Zeus ; then 
follows the circle of the Fiery star , called by the names 25 
both of Heracles and of Ares ; next comes the Glistening 
star , which some call sacred to Hermes, others sacred 

1 Arctic and * Antarctic arc not Aristotelian terms; cp. Meteor. 
362*32,33, 363 a 34, b 4, 3i. 

2 Cp. Meteor. 339 b 196*. 

3 i.e. aid ftp, ether , is here derived not from ufrWd.K, to blaze , but 
from del 6tlv, to be in continual motion ; cp. Plat. Craf. 4106, and 
de Caelo 270^22. 

B 2 

392 a DE MUNDO 

to Apollo ; after that is the circle of the * Light-bearing 
star , which some call the star of Aphrodite, others the 
star of Hera ; then comes the circle of the Sun, and lastly 
that of the Moon, which borders on the Earth. The ether 

3 encompasses the heavenly bodies and the area over which 
they are ordained to move. 

After the Ethereal and Divine Element, which we have 
shown to be governed by fixed laws and to be, moreover, 
free from disturbance, change, and external influence, there 
follows immediately an element which is subject through 
out to external influence and disturbance and is, in a word, 

35 corruptible and perishable. In the outer portion of this 

occurs the substance which is made up of small particles 

3Q2 b and is fiery, being kindled by the ethereal element owing 

to its superior size and the rapidity of its movement. In 

this so-called Fiery and Disordered Element flashes shoot 

and fires dart, and so-called beams l and pits 2 and 

comets have their fixed position and often become extin- 

5 guished. 

Next beneath this spreads the air, which is in its nature 
murky and cold as ice, but becomes illuminated and set 
on fire by motion, 3 and thus grows brighter and warm. 
And since the air too admits of influence and undergoes 

10 every kind of change, clouds form in it, rain-storms beat 
down, and snow, hoar-frost, hail with blasts of winds and 
of hurricanes, and thunder too and lightning and falling 
bolts, and the crashing together of countless opaque bodies. 

Next to the aerial element the earth and sea have 3 
15 their fixed position, teeming with plant and animal life, 
and fountains and rivers, either winding over the earth or 
discharging their waters into the sea. The earth is diver 
sified by countless kinds of verdure and lofty mountains 
and densely wooded copses and cities, which that intelli 
gent animal man has founded, and islands set in the 

1 trabcs of Seneca, Quaesf. Nat. i. I. 5, vii. 4. 3, Epp. 94. 56 ; Plin. ii. 
26. 26. 

2 Cp. Seneca. Quaest. Nat. i. 14. I. 

3 Q reads <eii>T]s for Kiv^a-fvs : Capelle, /. c., p. 536, adopts eVftV^f, 
but cp. above, 1. 2. 

CHAPTER 3 392 1 

sea and continents. Now the usual account divides the 20 
inhabited world into islands and continents, ignoring the 
fact that the whole of it forms a single island round which 
the sea that is called Atlantic flows. But. it is probable 
that there are many other continents separated from ours 
by a se.a that we must cross to reach them, some larger and 
others smaller than it, but all, save our own, invisible to 
us. For as our islands are in relation to our seas, so is 25 
the inhabited world in relation to the Atlantic, and so 
are many other continents in relation to the whole sea; 
for they are as it were immense islands surrounded by 
immense seas. The general element of moisture, covering 
the earth s surface and allowing the so-called inhabited 30 
countries to rise in patches as it were of dry land, may 
be said to come immediately after the aerial element. Next 
to it the whole earth has been formed, firmly fixed in the 
lowest position at the midmost centre of the Universe, 
closely compacted, immovable and unshakable. This l 
forms the whole of what we call the lower portion of the 35 

Thus then five elements, situated in spheres in five 393* 
regions,- the less being in each case surrounded by the 
greater namely, earth surrounded by water, water by 
air, air by fire, and fire by ether make up the whole 
Universe. All the upper portion represents the dwelling 
of the gods, the lower the abode of mortal creatures. Of 5 
the latter, part is rnoist, to which we are accustomed to give 
the names of rivers, springs, and seas ; while part is dry, 
which we call land and continents and islands. 

Of the islands, some are large, like the whole of what we 
call the inhabited world (and there are many other such 10 
surrounded by mighty seas) ; other islands are smaller, 
which are visible to us and in our own sea. Of these 
some are of considerable size, Sicily, Sardinia, Corsica, 
Crete, Euboea, Cyprus, and Lesbos ; others are less ex 
tensive, such as the Sporades and Cyclades and others 15 
bearing various names. 

Again, the sea which lies outside the inhabited world 

1 i. e. the earth and sea. 2 Cp. Meteor. 34o b 19 ff., 341 a 2 ff. 

393 a DE MUNDO 

is called the Atlantic or Ocean, flowing round us. Open 
ing in a narrow passage towards the West, at the so-called 
Pillars of Heracles, the Ocean forms a current into the 

20 inner sea, as into a harbour ; then gradually expanding it 
spreads out, embracing great bays adjoining one another, 
opening into other seas by narrow straits and then 
widening out again. First, then, on the right as one sails 
in through the Pillars of Heracles it is said to form two 

25 bays, the so-called Syrtes, the Greater and the Lesser 
as they are called ; on the other side it does not make 
such bays, but forms three seas, the Sardinian, the Gallic, 
and the Adriatic. Next to these comes the Sicilian sea, 
lying crosswise, and after it the Cretan. Continuing it 
come the Egyptian, Pamphylian, and Syrian seas in one 

30 direction, and the Aegean and Myrtoan seas in the other. 
Over against the seas already mentioned extends the 
Pontus, which is made up of several parts ; the innermost 
portion is called Maeotis, while the outer portion in the 
393 b direction of the Hellespont is connected by a strait with 
the so-called Propontis. Towards the East the Ocean 
again flows in and opens up the Indian 1 and Persian 
Gulfs, and displays the Erythraean sea- continuous with 
these, embracing all three. 3 With its other branch it passes 
5 through a long narrow strait and then expands again bound 
ing the Hyrcanian and Caspian country. Beyond this 
it occupies the large tract beyond the Lake of Maeotis ; 
then beyond the Scythians and the land of the Celts 
it gradually confines the width of the habitable world, as 

10 it approaches the Gallic Gulf and the Pillars of Heracles 
already mentioned, outside which the Ocean flows round 
the earth. In this sea are situated two very large islands, 
the so-called British Isles, Albion and lerne, which are 
greater than any which we have yet mentioned and lie 
beyond the land of the Celts. (The island of Taprobane 4 

15 opposite India, situated at an angle to the inhabited world, 
is quite as large as the British Isles, as also is the island 

1 The Gulf of Cutch or the Gulf of Cambay. 

2 The Arabian Sea. 

3 For the use of fiifiA^d* cp. 396* 31 and L. and S., s. ? ., ii. I, 2. 

4 Ceylon, cp. Strabo, xv. 14 (p. 690). 

CHAPTER 3 393" 

called Phebol 1 which lies over against the Arabian Gulf. 2 ) 
There is a large number of small islands round the British 
Isles and Iberia, forming a belt round the inhabited world, 
which as we have already said is itself an island. The 
width of the inhabited world at the greatest extent of its 
mainland is rather less than 40,000 stades, so the best 20 
geographers say, and its length about 70,000 stades." It 
is divided into Europe, Asia, and Libya. 

Europe is the tract bounded in a circle by the Pillars 
of Heracles, the inner recesses of the Pontus, and the 
Hyrcanian sea, where a very narrow isthmus stretches to 
the Pontus. Some have held that the river Tanais carries 25 
on the boundary from this isthmus. Asia extends from 
the said isthmus and the Pontus and the Hyrcanian sea 
to the other isthmus which lies between the Arabian Gulf 2 
and the inner sea, being surrounded by the inner sea and 
the Ocean which flows round the world. Some, however, 
define the bounds of Asia as from the Tanais to the 30 
mouths of the Nile. Libya extends from the Arabian 
isthmus to the Pillars of Heracles ; though some describe 
it as stretching from the Nile to the Pillars ; Egypt, which 394 a 
is surrounded by the mouths of the Nile, is given by some 
to Asia, by others to Libya ; some exclude the islands 
from both continents, others attach them to their nearest 

Such is our account of the nature of land and sea and 5 
their position the inhabited world as we call it. 

4 Let us now deal with the most remarkable conditions 
which are produced in and around the earth, summarizing 
them in the barest outline. There are two kinds of exhala 
tion 3 which rise continually from the earth into the air above 
us, namely, those 4 composed of small particles and entirely 10 
invisible, except when they occur in the east, and those 
which rise from rivers and streams and are visible. Of 
these the former kind being given off from the earth is 
dry and resembles smoke, while the latter being exhaled 
from the element of moisture is damp and vaporous. From 

1 Capelle, 1. c., p. 559, suggests Madagascar. 2 The Red Sea. 

5 Cp. Meteo? . 34i b 6ff. 4 Reading (at) ACTI-TO pf pels. 

394 a DE MUNDO 

15 the latter are produced mist and dew and the various 
forms of frost, clouds and rain and snow and hail ; while 
from the dry exhalation come the winds and the different 
kinds of breezes, and thunder and lightning, and hurricanes 
and thunderbolts, and all other cognate phenomena. Mist 

20 is a vaporous exhalation which does not produce water, 
denser than air but less dense than cloud ; it arises either 
from the first beginnings of a cloud or else from the 
remnant of a cloud. The contrary of this is what is called 
a clear sky, being simply air free from cloud and mist. 
Dew is moisture minute in composition falling from a clear 

25 sky ; ice is water congealed in a condensed form from 
a clear sky; hoar-frost is congealed dew, and dew-frost 
is dew which is half congealed. Cloud is a vaporous mass, 
concentrated and producing water. Rain is produced 
from the compression of a closely condensed cloud, vary 
ing according to the pressure exerted on the cloud ; when 

30 the pressure is slight it scatters gentle drops ; when it is 
great it produces a more violent fall, and we call this 
a shower, being heavier than ordinary rain, and forming 
continuous masses of water falling over earth. Snow is 
produced by the breaking up of condensed clouds, the 
cleavage taking place before the change into water ; it 
is the process of cleavage which causes its resemblance to 

35 foam and its intense whiteness, while the cause of its coldness 

is the congelation of the moisture in it before it is dis- 

394 b persed or rarefied. When snow is violent and falls heavily 

we call it a blizzard. Hail is produced when snow becomes 

densified and acquires impetus for a swifter fall from its 

close mass; the weight becomes greater and the fall more 

5 violent in proportion to the size of the broken fragments 

of cloud. Such then are the phenomena which occur as 

the result of moist exhalation. 

From dry exhalation, impelled into motion by cold, is 
produced wind ; for wind is merely a quantity of air set in 
motion in a mass. Wind is also called breath, a word 

10 used in another sense of the vital and generative substance 
which is found in plants and living creatures, and permeates 
all things ; but with this we need not deal here. The 



breath which breathes in the air we call wind, while to the 
expirations from moisture we give the name of breezes. 
The winds which blow from moist land we call land- 
winds , those which spring up from gulfs we call gulf- 15 
winds * ; somewhat similar to these are those which blow 
from rivers and lakes. Winds which are produced by the 
bursting of a cloud causing an expansion of its density in 
their own direction, 1 are called * cloud-winds . Those 
which are accompanied by a mass of water breaking forth 
are called rain-winds . 

The winds 2 which blow continuously from the rising sun 
are called Euri ; those from the north, Boreae ; those from 20 
the setting sun, Zephyri ; those from the south, Noti. Of 
the east winds, that which blows from the region of the 
summer sunrise is called Caecias ; that which blows from 
the region of the equinoctial sunrise is known as Apeliotes ; 
while the name of Eurus is given to the wind which blows 
from the quarter of the winter sunrise. Of the west winds, 
on the other hand, that which blows from the summer 25 
setting is Argestes, though some call it Olympias, 3 others 

1 Lit. which cause a dissolution of its density against themselves . 

2 The chart of the winds as given here is almost identical with that 
given in de Vent. Sit. et Appellat. (973 a ~ b ). 




E.Apcliohe5 ZephyrusW 





The following are the other principal passages describing the winds 
in classical authors : Aristot. Meteor. 363* 2-365* 13 ; Seneca, Ouaest. 
Nat. v. 1 6 ; Pliny, ii. 119 ff, ; Joannes Lydus, de Mensibus iv. 1 19. 

3 In de Vent. Sit. 973 b 2l Olympias is given as a synonym for 
Thracias, not for Argestes as here. 

394 b DE MUNDO 

lapyx ; that which blows from the equinoctial setting is 
Zephyrus, and that which blows from the winter setting 
is Lips. Of the north winds (Boreae) that which is next 
to Caecias is called Boreas in the specific sense of the 
word. 1 Aparctias 2 is next to it, and blows in a southerly 
30 direction from the pole. Thracias :j is the wind which 
blows next to Argestes ; by some it is called Circias. 4 Of 
the south winds, that which comes from the invisible pole 
and immediately faces Aparctias is called Notus ; that 
between Notus and Eurus is called Euronotus. The wind 
on the other side between Lips and Notus is called by some 
Libonotus, by others Libophoenix. 

35 Some winds are direct, those, that is, which blow along 
a straight line ; others follow a bending course, as for 
395 instance the wind called Caecias. 5 Some winds hold sway 
in the winter, the south winds for example ; others in the 
summer, such as the Etesian winds (Trade winds), which 
are a mixture of northerly and westerly winds. The 
so-called Ornithian G winds, which occur in the spring, are 
a northerly type of wind. 

5 Of violent blasts of wind, a squall is one which suddenly 
strikes down from above ; a gust is a violent blast which 
springs up in a moment ; a whirlwind, or tornado, is a 
wind which revolves in an upward direction from below. 
An eruption of wind from the earth is a blast caused by 
the emission of air from a deep hole or cleft ; when it 
10 comes forth in a whirling mass it is called an earth-storm . 
A wind which is whirled along in a dense watery cloud 
"and being driven forth 7 through it violently breaks up the 
continuous masses of the cloud, causes a roar and crash, 
which we call thunder, similar to the noise made by wind 

1 Called Meses in de Vent. Sit. 973*3-7, where see note. 

2 Called Boreas in de Vent. Sit. 

?l Reading QpaKias (R Gpanias ): cp. de Vent. Sit. 973* 17. 

4 Kam ay, the MS. reading, cannot possibly be right here, the name 
having been already given to the N. E. wind (394 b 22). 1 therefore 
read Kip/aW: cp. de Vent. Sit. 973 b 2O Qpaidas . . . eV St iraA/a KO\ 
t a Kip/any (emended by Rose for KipKas). 

6 Cp. Meteor. 364* 12. 

6 i.e. the winds which bring the birds of passage. . . 

7 Reading cco0-&V for 

CHAPTER 4 395 

driven violently through water. When the wind in break 
ing forth from a cloud catches fire and flashes it is called 15 
lightning. The lightning reaches our perception sooner 
than the thunder, though it actually occurs after it, since it 
is the mature of that which is heard to travel less quickly 
than that which is seen ; for the latter is visible at a 
distance, while the former is only heard l when it reaches 
the ear, especially since the one, the fiery element, travels 
faster than anything else, while the other, being of the nature 20 
of air, is less swift and only reaches the ear by actually 
striking upon it. 2 If the flashing body is set on fire and 
rushes violently to the earth it is called a thunderbolt ; if 
it be only half of fire, but violent also and massive, it is 
called a meteor ; if it is entirely free from fire, it is called 
a smoking bolt. 3 They are all called * swooping bolts , 25 
because they swoop down upon the earth. Lightning 4 
is sometimes smoky, and is then called smouldering 
lightning ; sometimes it darts quickly along, and is then 
said to be vivid ; at other times it travels in crooked 
lines, and is called forked lightning ; when it swoops 
down upon some object it is called swooping lightning . 

To sum up, some of the phenomena which occur in the 
air are merely appearances, while others have actual sub- 30 
stance and reality. Rainbows and streaks in the sky and 
the like are only appearances, while flashes and shooting- 
stars and comets and the like have real substance. A rain 
bow is the reflection of a segment of the sun or of the moon, 
seen, like an image in a mirror, in a cloud which is moist, 
hollow, and continuous in appearance, and taking a circular 35 

1 optafifvov is used in its proper sense in the clause in which it 
stands, and by a sort of zeugma for aKouo/ucroi/ in the next clause. 

2 Lightning is immediately seen by the eye, thunder can only be 
perceived by the ear when the original movement has set up other 
movements which eventually strike upon the ear. (Cp. de And. 
Soo a 6-i2.) 

3 Tixfxav cannot here be used (as in 400 a 29) of a violent storm , 
hurricane ; as applied to a thunderbolt, it seems to mean one which 
smokes, and to be connected with the verb n ^eti/, to smoke . 

4 The word Kepawns is used in Greek to mean either (i) a thunder 
bolt , or (2) lightning , which were more, or less identified by the 
Greeks. The context seems to show that it has the former meaning 
in 395 a 22, the latter in this passage. 

395 a DE MUNDO 

form. A streak is a rainbow appearing in the form of a 
straight line. A halo is an appearance oT brightness shining 
395 b roun< ^ a s * ar > it differs from a rainbow, because the latter 
appears opposite the sun and moon, while the halo is formed 
all round a star. A light in the sky is caused by the kindling 
of a dense fire in the air ; some lights shoot along, others 
5 are fixed. The shooting is the generation of fire by 
friction, when the fire moves quickly through the air and 
by its quickness produces an impression of length ; the 
fixture is a prolonged extension without movement, an 
elongated star as it were. A light which broadens out 
towards one end is called a comet. Some heavenly lights 

10 often last a considerable time, others are extinguished 
immediately. There are numerous other peculiar kinds 
of appearances seen in the sky, the so-called torches , 
beams , l barrels , and pits V which derive their names 
from their similarity to these objects. Some of them 
appear in the west, others in the east, others in both 

15 these quarters, but rarely in the north or south. None of 
them are subject to fixed laws ; for none of them have 
been discovered to be always visible in a fixed position. 
Such are the phenomena of the air. 

As the earth contains many sources of water, so also it 
contains many sources of wind and fire. Of these some 

20 are subterranean and invisible, but many have vents and 
spiracles, as Lipara, Etna, and the volcanoes of the Aeolian 
islands. Some of them frequently flow like rivers and cast 
up red-hot lumps. Some, which are under the earth near 
springs of water, warm them and cause some streams to 

25 flow- tepid, others very hot, others tempered to a pleasant 
heat. Similarly, many vent-holes for wind open in every 
part of the earth ; some of them cause those who draw 
near to them to become frenzied, others cause them to 
waste away, others inspire them to utter oracles, as at 
Delphi and Lebadia, 2 others utterly destroy them, as the 

30 one in Phrygia. 3 Often, too. a moderate wind engendered 

1 Cp. 392 b 4- 

2 Paus. ix. 39. 5 ; Strabo, ix. 2. 38 (p. 414) ; Philostratus, Vit.Apoll. 
viii. 19. 

3 Strabo, xiii. 4. u (p. 628). 

CHAPTER 4 395 b 

in the earth, being driven aside into distant holes and 
crannies of the earth and displaced from its proper locality, 
causes shocks in many parts. Often, too, a strong current 
from without becomes involved in the hollows of the earth, 
and, its exit being cut off, it shakes the earth violently, 
seeking an exit, and sets up the condition which we com- 35 
monly call an earthquake. Earthquakes of which the 
shock is oblique, at a sharp angle, are known as horizontal 396* 
earthquakes ; those which lift the earth up and down at 
right angles are known as heaving earthquakes ; those 
which cause the earth to settle down into hollows are called 
gaping earthquakes ; those which open up chasms and 
break up the earth s surface are called rending earth 
quakes . Some of them also emit winds, others stones or 5 
mud, while others cause springs to appear which did not 
exist before. Some earthquakes cause a disturbance by 
means of a single shock and are known as thrusting earth 
quakes . Others which swing to and fro and by inclinations 
and waves in each direction remedy the effect of their 
shock, are called ( vibrating earthquakes , setting up a 10 
condition which resembles trembling. There are also 
bellowing earthquakes , which shake the earth with a roar. 
Underground bellowing, however, is often heard unaccom 
panied by shocks, when the wind, though insufficient 
to cause a shock, is compressed together in the earth and 
beats with the force of its impetus. Blasts which penetrate 
into the earth are materialized also from moisture con- 15 
cealed underground. 

We find analogous phenomena occurring in the sea. 
Chasms form in it and its waters often retire or the waves 
rush in ; this is sometimes followed by a recoil and some 
times there is merely a forward surge of water, as is said to 20 
have occurred at Helice and Bura. 1 Often, too, there are 
exhalations of fire from the sea, and springs gush out and 
river-mouths are formed and trees suddenly grow up, and 
currents and eddies appear, like those caused in the air by 

1 An account of this tidal wave in northern Achaea in 373 B.C. 
is given by Strabo, viii. 7. 2 (p. 384), and Pausanias (vii. 25. 8) ; 
cp. also Meteor. 343** i, 17, 344 b 34, 368 b 6. 

396 a DE MUNDO 

25 blasts of wind, sometimes in the middle of the sea, some 
times in straits and channels. Many tides and tidal waves 
are said always to accompany the periods of the moon at 
fixed intervals. In short, owing to the mingling of the 
elements together, similar conditions are produced in the 
30 air and in the earth and in the sea, causing decay and 
generation in detail, but preserving the whole free from 
destruction and generation. 

Yet some have wondered how it is that the Universe, 5 
if it be composed of contrary principles namely, dry and 

35 moist, hot and cold has not long ago perished and been 
3g6 b destroyed. 1 It is just as though one should wonder how 
a city continues to exist, being, as it is, composed of 
opposing classes rich and poor, young and old, weak and 
strong, good and bad. They fail to notice that this has 
always been the most striking characteristic of civic con- 
5 cord, that it evolves unity out of plurality, and similarity 
out of dissimilarity, while it admits every kind and variety. 
It may perhaps be that nature has a liking for contraries 
and evolves harmony out of them and not out of similarities 
(just as she joins the male and female together and not 

10 members of the same sex), and has devised the origi 
nal harmony by means of contraries and not similarities. 
The arts, too, apparently imitate nature in this respect. 
The art of painting, by mingling in the picture the 
elements of white and black, yellow and red, achieves 

^representations which correspond to the original object. 
Music, too, mingling together notes, high and low, short 
and prolonged, attains to a single harmony amid different 
voices ; while writing, mingling vowels and consonants, 
composes of them all its art. The saying found in Hera- 

20 cleitus * the obscure was to the same effect : Junctions 
are : wholes and not wholes, that which agrees and that 
which differs, that which produces harmony and that which 
produces discord ; from all you get one and from one you 
get all. 2 

1 Cf. Seneca, Quaest. Nat. vii. 27. 3 ff. 

2 Reading a-wcn/acr (O R) o\a xai ofy oAa (P) with Diels, Vorsokr? 
i, p. 80, 1. 2. 

CHAPTER 5 39 6 b 

Thus then a single harmony orders the composition of 
the whole heaven and earth and the whole Universe by 
the mingling of the most contrary principles. The dry 25 
mingling with the moist, the hot with the cold, the light 
with the heavy, the straight with the curved, all the earth, 
the sea, the ether, the sun, the moon, and the whole heaven 
are ordered by a single power extending through all, which 
has created the whole universe out of separate and different 
elements air, earth, fire, and water embracing l them all 30 
on one spherical surface and forcing the most contrary 
natures to live in agreement with one another in the 
universe, and thus contriving the permanence of the whole. 
The cause of this permanence is the agreement of the 
elements, and the reason of this agreement is their equal 
proportion and the fact that no one of them is more 35 
powerful than any other, for the heavy is equally balanced 397 a 
with the light and the hot with the cold. Thus nature 
teaches us in the greater principles of the world that 
equality somehow tends to preserve harmony, whilst 
harmony preserves the universe which is the parent of all 
things and itself the fairest thing of all. For what created 
thing is more excellent ? Any that one can name is but 5 
a part of the ordered Universe. All that is beauteous bears 
its name, and all that which is arranged well, for it is said 
to be well * ordered , being thus called after the * ordered 
Universe. 2 And what subordinate phenomenon could be 
likened to the ordered system of the heavens and the 
march of the stars and the sun and the moon, which move I0 
on in unvarying measure through age after age ? Where 
else could be found such regularity as is observed by the 
goodly seasons, which produce all things and bring in due 
order summer and winter, day and night, to the accomplish 
ment of the month and the year ? Moreover, in greatness 
the universe is pre-eminent, in motion swiftest, in radiance 15 
most bright, and in might it knows not old age or corrup 
tion. It has divided the various creatures that live in the sea, 
on the earth, and in the air, and regulated their lives by its 

1 For this use of omXa/^uW cp. 393 4 and note. 

2 Cp. 39i b IO-H. 


movements. Of it all living things breathe and have their 

20 life. Even all the unexpected changes which occur in it are 
really accomplished in an ordered sequence diverse winds 
conflicting together, thunderbolts falling from heaven, and 
violent storms bursting forth. The expulsion of moisture 
and the exhalation of fire by these means restores the 
whole to harmony and stability. The earth, too, clothed 

25 with diverse vegetation, gushing forth with streams and 
trodden by the feet of living creatures, in due season 
bringing forth, nurturing, and receiving back all things, 
producing countless varieties and changes, none the less 
always preserves its nature untouched by age, though 
shaken by earthquakes, washed. by floods, and in parts 

3 o burnt up by fires. All these things seem to work its 
welfare and to ensure its eternal permanence. For when 
it is shaken by earthquakes, the winds which have t>een 
diverted into it escape forth, finding vents through the 
clefts, as we have already said ; 1 when it is washed by rain, 
it is cleansed of all that is unhealthy : and when the breezes 

35 blow about it, it is purified above and beneath. Again, 

397 b the fires soften that which is frost-bound, while the frosts 

abate the fires. Of individual things upon the earth some 

are coming into being, others are at their prime, others are 

decaying ; and birth checks decay and decay lightens birth. 

5 Thus an unbroken permanence, which all things conspire to 
secure, counteracting one another at one time dominating, 
at another being dominated preserves the whole unim 
paired through all eternity. 

There still remains for us to treat briefly, as we have 6 

10 discussed the other subjects, of the cause which holds all 

things together. For in dealing with the universe, not 

perhaps in exact detail, yet at any rate so as to give a 

general idea of the subject, it would be wrong to omit that 

which is the most important thing in the universe. The 

old explanation which we have all inherited from our 

fathers, is that all things are from God and were framed 

15 for us by God, and that no created thing is of itself sufficient 

1 Cp. 395 b 2o. 

CHAPTER 6 397 b 

for itself, deprived of the permanence which it derives from 
him. Therefore some of the ancients went so far as to 
say that all those things are full of God which are pre 
sented to us through the eyes and the hearing and all the 
other senses, thus propounding a theory which, though it 
accords with the divine power, does not accord with the 20 
divine nature. For God is in very truth the preserver and 
creator of all that is in any way being brought to perfection 
in this universe; yet he endures not all the weariness of 
a being that administers and labours, but exerts a power 
which never wearies ; whereby he prevails even over things 
which seem far distant from him. He hath himself ob 
tained the first and highest place and is therefore called 25 
Supreme, and has, in the words of the poet, 

Taken his seat in heaven s topmost height ; 1 

and the heavenly body which is nighest to him most 
enjoys his power, and afterwards the next nearest, and so 
on successively until the regions wherein we dwell are 
reached. Wherefore the earth and the things upon the 
earth, being farthest removed from the benefit which 30 
proceeds from God, seem feeble and incoherent and full 
of much confusion ; nevertheless, inasmuch as it is the 
nature of the divine to penetrate to all things, the things 
also of our earth receive their share of it, and the things 
above us according to their nearness to or distance from 35 
God receive more or less of divine benefit. It is therefore 39& a 
better, even as it is more seemly and befitting God, to 
suppose that the power which is stablished in the heavens 
is the cause of permanence even in those things which 
are furthest removed from it in a word, in all things, 
rather than to hold that it passes forth and travels to and 5 
fro to places which become and befit it not, and personally 
administers the affairs of this earth. For indeed, to super 
intend any and every operation does not become even the 
rulers among mankind the chief, for example, of an army 
or a city, or the head of a household, if it were necessary 
to bind up a sack of bedding or perform any other some- 


398 a DE MUNDO 

10 what menial task, such as in the days of the Great King 
would not be performed by any ordinary slave. Nay, we 
are told that the outward show observed by Cambyses and 
Xerxes and Darius was magnificently ordered with the 
utmost state and splendour. The king himself, so the story 
goes, established himself at Susa or Ecbatana, invisible to 

15 all, dwelling in a wondrous palace within a fence gleaming 
with gold and amber and ivory. And it had many gate 
ways one after another, and porches many furlongs apart 
from one another, secured by bronze doors and mighty 
walls. Outside these the chief and most distinguished 
men had their appointed place, some being the king s 

20 personal servants, his bodyguard and attendants, others the 
guardians of each of the enclosing walls, the so-called 
janitors and listeners , that the king himself, who was 
called their master and deity, might thus see and hear all 
things. Besides these, others were appointed as stewards of 

25 his revenues and leaders in war and hunting, and receivers 
of gifts, and others charged with all the other necessary 
functions. All the Empire of Asia, bounded on the west 
by the Hellespont and on the east by the Indus, was 
apportioned according to races among generals and satraps 

30 and subject-princes of the Great King ; and there were 
couriers and watchmen and messengers and superintendents 
of signal-fires. So effective was the organization, in 
particular the system of signal-fires, which formed a chain 
of beacons from the furthest bounds of the empire to Susa 
and Ecbatana, that the king received the same day the 

35 news of all that was happening in Asia. Now we must 
3g8 b suppose that the majesty of the Great King falls as far short 
of that of the God who possesses the universe, as that of 
the feeblest and weakest creature is inferior to that of the 
king of Persia. Wherefore, if it was beneath the dignity 
of Xerxes to appear himself to administer all things and 
5 to carry out his own wishes and superintend the govern 
ment of his kingdom, such functions would be still less 
becoming for a god. Nay, it is more worthy of his dignity 
and more befitting that he should be enthroned in the 
highest region, and that his power, extending through the 

CHAPTER 6 398 b 

whole universe, should move the sun and moon and make 
the whole heaven revolve and be the cause of permanence 
to all that is on this earth. For he needs no contrivance 10 
or the service of others, as our earthly rulers, owing to their 
feebleness, need many hands to do their work ; but it is most 
characteristic of the divine to be able to accomplish diverse 
kinds of work with ease and by simple movement, even as 
past masters of a craft by one turn of a machine accomplish 15 
many different operations. And just as puppet-showmen 
by pulling a single string make the neck and hand and 
shoulder and eye and sometimes all the parts of the figure 
move with a certain harmony ; so too the divine nature, 
by simple movement of that which is nearest to it, imparts ^o 
its power to that which next succeeds, and thence further 
and further until it extends over all things. For one thing, 
moved by another, itself in due order moves something 
else, each acting according to its own constitution, and not 
all following the same course but different and various and 25 
sometimes even contrary courses ; although the first im 
pulse, as it may be called, was directed to a single form of 
motion. It is just as though one should cast from one 
vessel at the same time a sphere, a cube, a cone, and a 
cylinder ; each of them will move according to its particular 
shape. Or if one should hold in the folds of a garment 30 
a water-animal, a land-animal, and a bird, and let them go ; 
clearly the animal that swims will leap into its own element 
and swim away, the land-animal will creep away to its 
own haunts and pastures, the bird of the air will raise itself 
aloft from the earth and fly away, though one original 
cause gave each its aptitude for movement. So is it with 35 
the universe ; by a single revolution of the whole within 399 C 
the bounds of day and night, the different orbits of all the 
heavenly bodies are produced, though all are enclosed in 
a single sphere, some moving more quickly, others more 
slowly, according to the distances between them and the 5 
individual composition of each. For the moon accomplishes 
her circuit in a month, waxing and waning and disappearing ; 
the sun and the heavenly bodies whose course is of equal 
length, namely those called the Lightbearer and Hermes, 

C 2 

399 a DE MUNDO 

perform their revolution in a year ; the Fiery star in 

10 double that period ; the star of Zeus in six years ; and 
lastly the so-called star of Cronos in a period two and a 
half times as long as the heavenly body next below it. 
The single harmony produced by all the heavenly bodies 
singing and dancing together springs from one source and 
ends by achieving one purpose, and has rightly bestowed 
the name not of * disordered but of ordered universe 

15 upon the whole. And just as in a chorus, when the leader 
gives the signal to begin, the whole chorus of men, or it 
may be of women, joins in the song, mingling a single 
studied harmony among different voices, some high and 
some low ; so too is it with the God that rules the whole 
world. For at the signal given from on high by him who 

20 may well be called their chorus-leader, the stars and the 
whole heaven always move, and the sun that illumines all 
things travels forth on his double course, whereby he both 
divides clay and night by his rising and setting, and also 
brings the four seasons of the year, as he moves forwards 
towards the north and backwards towards the south. And 
in their own due season the rain, the winds, and the dews, 

25 and all the other phenomena which occur in the region 
which surrounds the Earth, are produced by the first, 
primaeval cause. These are followed by the flowing of 
rivers, the swelling of the sea, the growth of trees, the 
ripening of fruits, the birth of animals, the nurturing and 
the prime and decay of all things, to which, as I have said, 

30 their individual composition contributes. When, therefore, 
the ruler and parent of all, invisible save to the mind of the 
eye, gives the word to all nature that moves betwixt heaven 
and earth, the whole revolves unceasingly in its own circuits 
and within its own bounds, sometimes unseen and some 
times appearing, revealing and again hiding diverse manners 

35 of things, from one and the same cause. Very like is it to 

399 b that which happens in times of war, when the trumpet 

sounds to the army ; then each soldier hears its note, and 

one takes up his shield, another dons his breast-plate ; 

another puts on his greaves or his helmet or his sword- 

5 belt ; one puts the bit in his horse s mouth, another mounts 

CHAPTER 6 399 b 

his chariot, another passes along the watchword ; the 
captain betakes himself straightway to his company, the 
commander to his division, the horseman to his squadron, 
the light-armed warrior hastens to his appointed place ; all 
is hurry and movement in obedience to one word of com 
mand, to carry out the orders of the leader who is supreme 
over all. Even so must we suppose concerning the universe ; 10 
by one impelling force, unseen and hidden from our eyes, 
all things are stirred and perform their individual functions. 
That this force is unseen stands in the way neither of its 
action nor of our belief in it. For the spirit of intelligence 
whereby we live and dwell in houses and communities, 
though invisible, is yet seen in its operations; for by it the 15 
whole ordering of life has been discovered and organized 
and is held together the ploughing and planting of the 
earth, the discovery of the arts, the use of law, the ordering 
of constitutions, the administration of home affairs and war 
outside our borders and peace. Thus, too. must we think of 
God, who in might is most powerful, in beauty most fair, ^o 
in time immortal, in virtue supreme ; for, though he is 
invisible to all mortal nature, yet is he seen in his very 
works. For all that happens in the air, on the earth, and 
in the water, may truly be said to be the work of God, 
who possesses the universe; from whom, in the words of 25 
Empedocles, the natural philosopher, 

Whatsoever hath been and is now and shall be hereafter, 
All alike hath its birth men, women, trees of the forest, 
Beasts of the field and fowls of the air and fish in the water. 1 

To use a somewhat humble illustration, we might with 
truth compare the ordering of the universe to the so-called 
key-stones in arches, which, placed at the junction of the rj 
two sides, ensure the balance and arrangement of the whole 
structure of the arch and give it stability. Moreover, they 
say that the sculptor Pheidias, when he was setting up the 
Athena on the Acropolis, represented his own features in 
the centre of her shield, and so attached it to the statue by 35 
a hidden contrivance, that any one who tried to cut it out. 400 

1 Diels, Vorsokr? i, p. 233, 9-11. 

400 a ^ DE MUNDO 

thereby necessarily shattered and overthrew the whole 
statue. 1 The position of God in the universe is analogous 
to this, for he preserves the harmony and permanence of all 
things ; save only that he has his seat not in the midst, 
5 where the earth and this our troubled world is situated, but 
himself pure he has gone up into a pure region, to which 
we rightly give the name of heaven, for it is the furthest 
boundary 2 of the upper world, and the name of Olympus, 
because it is all-bright 3 and free from all gloom and 
disordered motion, such as is caused on our earth by 
10 storms and the violence of the wind. Even thus speaks 
the poet Homer 

Unto Olympus height, where men say that the gods have 

their dwelling, 

Alway safe and secure ; no wind ever shaketh its stillness, 
Nor is it wet with the rain ; no snow draweth nigh ; but 

Ever the air is outspread, and a white sheen floateth 

about it. 4 

15 This, too, is borne out by the general habit of mankind, 
which assigns the regions above to God ; for we all stretch 
up oun hands to heaven when we offer prayers. Wherefore 
these words of the poet are not spoken amiss, 

Heaven belongcth to Zeus, wide spread mid the clouds 
and the ether/ 

20 Therefore also the objects of sense which are held in the 
highest esteem occupy the same region, to wit the stars and 
the sun and moon. For this cause the heavenly bodies 
alone are so arranged that they ever preserve the same 
order, and never alter or move from their course, while the 
things of earth, being mutable, admit of many changes 

25 and conditions. For ere now mighty earthquakes have 
rent the earth in diverse places, and violent rains have 
burst forth and flooded it, and the inroads and withdrawals 

1 Cp.tteM/ r. A use. 846* 19 flf. ; Plut. Pericles 31 ; Cic. Titsc. i. 15, 34 ; 
Val. Max. viii. 14. 6 ; and for the Strangford shield, which is a copy 
of the shield of the Athena Parthenos, see A. H. Smith, Cat. of Gk. 
Sculpt if re in the Brit. Mus. i, no. 302. 

2 nvpavos is here derived from opor, boundary . 

s "OAv/iTTo? is here derived from oAo? and Aa^nm , to shine . 

1 Od. vi. 42-45. 5 //. xv. 192. 

CHAPTER 6 400* 

of waves have often turned the dry land into sea and sea 
into dry land, and the might of winds and hurricanes has 
sometimes overthrown whole cities, and fires and flames have 
consumed the earth, either coming forth from heaven in 30 
former times, even as men say that in the days of Phaethon 
they burnt up the eastern regions of the earth, or else 
gushing forth and breathing from the earth in the west, 
as when the craters of Etna burst and flowed like a torrent 
over the earth. (There also the favour of heaven bestowed 
especial honour upon the generation of the pious, when they 
were overtaken by the fiery stream, because they were 
carrying their aged parents upon their shoulders and seeking 
to save them. For when the river of fire drew near to 
them, it was parted asunder and turned part of its flame 
this way and part that way, and preserved the young men 5 
and their parents unscathed. 1 ) 

To sum up the matter, as is the steersman in the ship, 
the charioteer in the chariot, the leader in the chorus, law 
in the city, the general in the army, even so is God in the 
Universe ; save that to them their rule is full of weariness 
and disturbance and care, while to him it is without toil or 10 
labour and free from all bodily weakness. For, enthroned 
amid the immutable, he moves and revolves all things, 
where and how he will, in different forms and natures ; just 
as the law of a city, fixed and immutable in the minds of 
those who are under it, orders all the life of the state. For 15 
in obedience to it, it is plain, the magistrates go forth to 
their duties, the judges to their several courts of justice, 
the councillors and members of the assembly to their 
appointed places of meeting, and one man proceeds to his 
meals in the prytaneum, another to make his defence before 20 
the jury, and another to die in prison. So too the custo 
mary public feasts and yearly festivals take place, and 
sacrifices to the gods and worship of heroes and libations 
in honour of the dead. The various activities of the 
citizens in obedience to one ordinance or lawful authority 
are well expressed in the words of the poet, 

And all the town is full of incense smoke, 35 

And full of cries for aid and loud laments. 2 
1 Cp. Lycurg. in Leocr. 95-96. 2 Soph. O. T. 4, 5. 

4 oo b DE MUNDO 

So must we suppose to be the case with that greater 
city, the universe. For God is to us a law, impartial, 
admitting not of correction or change, and better, me- 
30 thinks, and surer than those which are engraved upon 
tablets. Under his motionless 1 and harmonious rule the 
whole ordering of heaven and earth is administered, extend 
ing over all created things through the seeds of life in each 
both to plants and to animals, according to genera and 

4<Di a species. For vines and date-palms and peach-trees and 
sweet fig-trees and olives 2 , as the poet says, and trees 
which, though they bear no fruits, have other uses, plane- 

, trees and pines and box-trees, 

Alder and poplar-tree and cypress breathing sweet odours, 3 

5 and trees which produce autumn crops pleasant but also 
difficult to store, 

Pear-trees and pomegranate-trees and apple-trees glorious- 
fruited, 4 

and animals, both wild and tame, feeding in the air or 
on the earth or in the water, all are born and come to 

I0 their prime and decay in obedience to the ordinances of 
God ; for, in the words of Heraclitus, every creeping thing 
grazes at the blow of God s goad . 5 

God being one yet has many names, being called after 7 
all the various conditions which he himself inaugurates. 
We call him Zen and Zeus, using the two names in the . 

, 5 same sense, as though we should say him through whom 
we live . 6 He is called the son of Kronos and of Time, for 
he endures from eternal age to age. He is God of Light 
ning and Thunder, God of the Clear Sky and of Ether, 
God of the Thunderbolt and of Rain, so called after the 
rain and the thunderbolts and other physical phenomena. 
Moreover, after the fruits he is called the Fruitful God, 

20 after cities the City-God : he is God of Birth, God of the 
House-court, God of Kindred and God of our Fathers 

1 Reading aicivijTtos with O. 2 Od. xv. 116. 

3 ib. v. 64. 4 ib. xi. 589. 

6 Reading TrXrjyfi for n}v yrjv with Diels, Vorsokr? i, p. 80, 1. 8. 
6 i.e. Zeus is here derived from }", to live , and its accusative Am, 
apparently, from the preposition did. 

CHAPTER 7 40i a 

from his participation in such things. He is God of Com 
radeship and Friendship and Hospitality, God of Armies 
and of Trophies, God of Purification and of Vengeance and 
of Supplication and of Propitiation, as the poets name 
him, and in very truth the Saviour and God of Freedom, 
and to complete the tale of his titles, God of Heaven and 25 
of the World Below, deriving his names from all natural 
phenomena and conditions, inasmuch as he is himself the 
cause of all things. Wherefore it is well said in the Orphic 

Zeus of the flashing bolt was the first to be born and 

the latest, 
Zeus is the head and the middle ; of Zeus were all 

things created ; 
Zeus is the stay of the earth and the stay of the star- 4 O1 

spangled heaven ; 

Zeus is male and female of sex, the bride everlasting ; 
Zeus is the breath of all and the rush of unwearying fire ; 
Zeus is the root of the sea, and the sun and the moon 

in the heavens ; 
Zeus of the flashing bolt is the king and the ruler of 5 

all men, 
Hiding them all away, and again to the glad light of 

Bringing them back at his will, performing terrible 

marvels. 1 

I think also that God and nought else is meant when 
we speak of Necessity, which is as it were invincible 2 
being ; and Fate, because his action is continuous 3 and he 
cannot be stayed in his course ; and Destiny, 4 because all 10 
things have their bounds, and nothing which exists is 
infinite; and Lot." from the fact that all things are allotted; 
and Nemesis, from the apportionment which is made to 
every individual ; and Adrasteia, 7 which is a cause ordained 
by nature which cannot be escaped ; and Dispensation, 8 so 

1 Kaibel, Orphica, 46. 

2 Ai/a-yifi;, necessity , is here derived from ai/iKi/ror, invincible . 

3 Elfjuipfifvij, fate , from fipfu/, to plait together . 
* lit TrpotyieVr;, destiny , from nt /juroOr, to bound . 

5 Motpa, lot , from pepi^fU , to allot . 

6 Ntpfo-is, from W/netr, to apportion . 

7 Afyaoreia, from n-, not , and ftiSpuo-Ktiv, to run away . 

8 Aura, dispensation , from del ovaa, ever existing . 

40i b DE MUNDO 

called because it exists for ever. What is said of the Fates 
15 and their spindle tends to the same conclusion ; for they 
are three, appointed over different periods of time, and the 
thread on the spindle is part of it already spent, part 
reserved for the future, and part in the course of being 
spun. One of the Fates is appointed to deal with the 
past, namely, Atropos, for nothing that is gone by can be 
20 changed 1 ; Lachesis is concerned with the future, for ces 
sation 2 in the course of nature awaits all things ; Clotho 
presides over the present, accomplishing and spinning 3 for 
each his own particular destiny. This fable is well and 
duly composed. All these things are nought else but God, 
even as worthy Plato tells us. 4 

25 God, then, as the old story has it, holding the beginning 
and the end and the middle of all things that exist, pro 
ceeding by a straight path in the course of nature brings 
them to accomplishment ; and with him ever follows 
Justice, the avenger of all that falls short of the Divine 
Law Justice, in whom may he that is to be be happy, be 
from the very first a blessed and happy partaker ! 

r, from -, not , and r/jcVeip, to turn . 
s-, from Xr/ytiv, to cease . 

3 KAo>$a>, from KXw&tv, to spin . 

4 The reference appears to be to the account of the Fates given in 
the Vision of Er (Plato, Rep. 617 c). 


3QQ b . OO a -OI b = 

Acropolis, 9 b 34. 

Adrasteia, oi b i3. 

Adriatic, 3*28. 

Aegean, 3 a 3o. 

Aeolian Islands, 5 b 2i. 

Aerial element, see Air. 

Air, aerial element, 2 b 5-14, 32, 3*2, 

6 b 29, o ; b 24. 

Albion (Great Britain), 3 b l2. 
Alexander, i a 2. 
Aloadae, l a ii. 
Animals, movements of different, 

8 b 30735- 

Antarctic pole, 2 a 4. 

Aparctias, 4 b 29, 32. 

Apeliotes, 4 b 23- 

Aphrodite, 2 !1 28. 

Apollo, 2 a 27. 

Arabian, Gulf (Red Sea), 3 b i6, 28 ; 

Sea (Erythraean), 3 b 4 ; Isthmus, 

3 b 28, 32. 

Arch, keystone of an, 9 30. 
Arctic pole, 2 a 3. 
Ares, 2 a 35. 
Argestes, 4 b 2$, 30. 
Armies, Cod of, oi a 22. 
Army, Universe compared to an, 

9 b i ff. 
Arts, analogy of the, 6 b n, 8 b 14- 

Asia, 3 b 22, 4 a 2, 8 a 27, 35; its 

boundaries, 3 b 26-31. 
Athena Parthenos, 9 b 34. 
Atlantic, 2 b 22, 27, 3 a l6. 
Atropos, oi b i8. 
Axis (of the Universe), i b 26. 

Barrels , 5 b i2. 

Beacon fires, Persian system of, 

8 a 3i-35. 

Beaming Star , * the , 2 a 24. 
Beams , 2 b 4, 5 b i2. 
Bellowing, subterranean, 6 a i3- 
Birth, God of, (Zeus), oi a 20 ; and 

decay on the earth, 7 b 3~5, 9 a 28, 


Blizzard, 4 b l. 

Bolt, see Thunderbolt. 

Boreas, 4 b 20, 28, 29, 5 a 3, 4. 

Breath, 4 b 9-i2. 

Breezes, 4 a 17, b i3, 7 a 34- 

Britain, British Isles, 3 b i2, 17. 

Bura, 6 a 2l. 

Caecias, 4 b 22, 28, 5 a i. 
Cambay, Gulf of (?), 3^3. 
Cambyses, 8 a u. 
Caspian district, 3 b 6. 
Celts, land of the, 3 b 9, 13. 
Ceylon (Toprobane), 3 b i4- 
Chorus, harmony in a, 9 a i5-l8; 

chorus-leader, God compared to 

a, 9 a i9, oo b 7. 
Circias, 4 1> 3I. 
City, the Universe compared to a, 

6 b i ff., oo b 8, 14-30. 
City-god, the, (Zeus), oi a 2o. 
Clear Sky, 4 a 22, 24 ; God of the, 

(Zeus), oi a i7. 
Clotho, oi b 2i. 
Cloud, 2 b 9, 4 a 16, 21, 23, 26, 28, 29, 

33, b 6, 17, 5 a n, I2 > 15, 33- 
Cloud winds , 4 b i8. 
Comets, 2 b 4, 5 a 32, b 8~9. 
Comradeship, God of,(Zeus), oi a 22. 
Consonants, 6 b l8, 
Continents, our world one of many, 

2 b 20, 3 ;1 IO. 

Contraries, in the Universe, 6 a 34 ; 
in a city, 6 b 2-4 ; harmony evolved 
out of, 6 b 8, 1 1 , 23-25 ; nature has 
a liking for, 6 h 7. 

Corsica, 3 a 13. 

Corycian cave, I a 2i. 

Creator, God as, 7 b 13-24. 

Cretan Sea, 3 a 29. 

Crete, 3 a i3- 

Cronos, 2 a 24, 9*11, oi a i5. 

Cutch, Gulf of (?), 3 b 3. 

Cyclades, 3 a i4. 

Cyprus, 3 a i3. 

Cyrnus (Corsica), 3 a i3- 


Darius, 8 a n. 

Decay, birth and, on the earth, 

7 b 3~5> 9 a 28, 29. 
Delphi, 5 1 29. 
Destiny, oi b io. 
Dew, 4 a i5, 23, 26, 9*25. 
Dew-frost , 4* 26. 
Disordered element, the, (fire), 2 b 2. 
Dispensation, oi b i4. 
Dissimilarity, similarity evolved 

from, 6 b 5. 
Divine Law, oi b 28. 

Earth, the, I b 9, 2*29, b i4, 3 a 2, 
b 27, 30, 7 a 24- b 5, 8 b io, 9 b 24, 
oo a 23 ; the centre of the Uni 
verse, i b i2, 2 b 33, oo :i 5 ; God s 
rule of, 7 b 29~8 a 7; phenomena 
in and around, 4 a 7 ff., 9 a 25-30 ; 
sources of water, wind, and fire 
in, 5 b i8ff. 

Earthquakes, 5 b 33 - 6 a 16, 7 a 28, 
31, oo 1 25 ; bellowing , 6 a n; 
gaping , 6 a 4 ; heaving , 6 a 3 ; 
horizontal , 6 a i; rending , 6 a 5 ; 
* thrusting , 6 a 8 ; vibrating , 
6 a io. 

Earth-storm , 5 a 10. 

East winds, 4 b 20, 22-24, 33- 

Ecbatana, 8 a i4, 34. 

Egypt, 4* I. 

Egyptian Sea, 3 a 29. 

Elements, i b io, 3 a i, 6 a 28; their 
agreement in the Universe, 6 b 2 5- 
7 a 5. See also Air, Earth, Ether, 
Fire, Water. 

Empedoclcs quoted, 9 b 25-28. 

Equality preserves harmony, 7 a 3. 

Erythraean (Arabian) Sea, 3 b 4- 

Eternal, God is, oi a i6. 

Etesian winds, 5 a 2. 

Ether, ethereal element, 2 b i, 6 b 27 ; 
its nature, 2*31, 32; is the sub 
stance of the stars and heaven, 
2 a 5 ; surrounds the heavenly 
bodies, 2*30; its motion, 2 a 8, 
b 2 ; etymology of the word, 2 a 6-8. 

Etna, 5 b 2i, oo a 33. 

Euboea, 3 a i3- 

Euronotus, 4 b 33. 

Europe, 3 b 22; its boundaries, 3 b 23- 

Eurus, 4 b 2o 22, 24, 33. 

Exhalations, 4 a 9~ b i8, 7 a 23. 

Fate, oi b 9. 

Fates, the, oi b i4~24. 

Fathers, God of Our, (Zeus), oi a 21. 
Fiery Star , the, 2 a 25, 9 a Q. 
Fire, fiery element, 2 a 33-5, 3 a 3, 

5 a 20, 6 b 30, 7 a 23, 29, b i, 2, 00*29, 

30; darting fires, 2 b 3; subter 

ranean fires, 5 b i9ff. 
Fixed, stars, 2 a io, n, 23, lights in 

the sky, 5 b 4, 7. 
Flashes in the sky, 5 a 3i. 
Floods, 7 a 29, oo a 26, 27. See also 

7*i dal waves. 

Freedom, God of, (Zeus), oi a 24. 
Friendship, God of, (Zeus), oi a 22. 
Frost, 4 a i6, 7 b i ; hoar-frost, 4 a 26 ; 

dew-frost , 4 a 26. 
Fruitful God, the, (Zeus), oi a 19. 

Gallic Sea, 3 a 27, b 9. 

Geographers, 3 b 20. 

General, God compared to a, oo b 8. 

Glistening Star , the, 2 a 26. 

God, his position in the Universe, 
7 b 9fT., 9 b 28 ff. ; his rule over the 
earth, 7 b 29-8"* 7, oo b 9~i I, 27-34 ; 
is eternal, oi a i6, supreme, 7 b 26; 
as creator, 7 b 13-24; the nature 
of his power, 8 b 8-10, 19, 22, l) l i- 
28 ; needs no help from others, 
8 b io-i6 ; brings all things to ac 
complishment, oi b 25-27 ; dwells 
in the highest part of the Uni 
verse, 7 b 26, 27, 8 h 7, oo a 4-2i ; 
compared to a chorus leader, 
9 a i9,oo b 7, to a general, oo b 8, 
to human law, oo b 8, 14-30, to the 
keystone of an arch, 9 b 3o, to 
the King of Persia, 8 H I iff., to a 
steersman, oo b 6; identified with 
Adrasteia, oi b i3, with Destiny, 
oi b io, with Dispensation, oi b 14, 
with Fate, oi b 9, with the Fates, 
oi b i4-24, with Lot, oi b i2, with 
Necessity, oi b 8, with Nemesis, 
oi b i2; his various titles, oi a !2- 

Gulf winds , 4 b i5. 
Gusts of wind, 5 a 6. 

Hail, 2 b 11, 4 a 16, b i-5- 

Halo, 5 a 36- b 3. 

Harmony, evolved out of contraries, 
6 b 8, u, 23-25; preserved by 
equality, 7 a 3 ; in music, 6 b 15-17, 
9 a 15-18; in the Universe, 6 b 

Heaven, i b 9, 6 b 28, 7 a 9, 8 b 9, 9 a 20; 
the highest part of the Universe, 


i b 1 6 ; composed of ether, 2 a 5 ; 
is spherical, i b 20 ; its movement, 
i b 17-19 ; God of H., (Zeus), oi a 

Helice, 6*21. 

Hellespont, 3 b i, 8 a 2;. 

Hera, 2 a 28. 

Heracles, 2 a 35 ; Pillars of, 3 a i8, 

24, b io, 23, 32, 4 a i. 
Heraclitus quoted, 6 b 20-22, oi a 


Hermes, 2 a 26, 9 a 9. 
Hoar-frost, 2 b 10, 4*26. 
Homer quoted, 7 b 27, oo a 10-14, 19, 

oi a 4, 7. 

Hospitality, God of, (Zeus), oi a 22. 
House-court, God of the, (Zeus), 

oi a 20. 

Hurricane, 2 b u, 4 b 18, oo !l 29. 
Hyrcanian, district, 3 b 6 ; Sea, 3 b 24, 


lapyx, 4 b 26. 

Iberia, 3 b 16. 

Ice, 4*25. 

lerne (Ireland), 3 b 13. 

India, 3 b 15. 

Indian Gulf, 3 b 3. 

Indus, 8*28. 

Intelligence, 9 b 13. 

Ireland (lerne), 3 b 13. 

Island, our continent is an, 2 b 2i, 

3 b 18 ; names of islands, 3 a 9-15, 

b ii-i7; islands at the mouth of 

the Nile, 4 :i 3. 
Isthmus, between Hyrcanian Sea 

and Pontus, 3 b 25-27; Arabian, 


Justice, oi b 27. 

Keystone of an arch, 9 b 30. 
Kindred, God of, (Zeus), oi a 2i. 
King of Persia, 8 a 10, 30, b i. 

Lachesis, oi b 2o. 

* Land winds , 4 b 14. 

Lathe, turner s, i b 22. 

Law, 9 b 18 ; divine law, oi b 28 ; 

God compared to human law, 

oo b 8, 14-30. 
Lebadia, 5 b 29. 
Lesbos, 3 a 14. 
Libonotus, 4 b 34. 
Libophoenix, 4 b 34. 
Libya, 3 b 22 ; its boundaries, 3 b 31- 

4 a 4 . 

Light-bearing star , the, 2 a 27, 
9 a 8. 

Lightning, 2 b 12, 4 a 18, 5 a 15 ; 
reaches our perception before 
thunder, 5 a 16-21 ; forked , 5* 
27; smouldering , 5 a 26; swoop 
ing , 5 a 28 ; * vivid , 5 a 27 ; Zeus, 
god of L., oi a 17. 

Lights in the sky, 5 a 3-18. 

Li para, 5 b 21. 

Lips, 4 b 27, 34. 

Lot, oi b 12. 

Maeotis, 3 a 32, b 8. 
Mist, 4 a i5, 19, 23. 
Moisture, 7 a 22; element of M., 

2 b 3o, 4 :l i4. 
Moon, 2 a 29, 5 a 33, b 2, 6 b 28, 7 a 10, 

S b 9, 9 a 6, 7, oo a 2i ; its effect on 

tides, 6 a 26, 27. 
Motion, movement, of different 

animals, 8^*30-35 ; of the heavens, 

i a 17-19, oo a 21-23 J f spheres, 

cubes, cones, and cylinders, b b 

27-29 ; in the universe, i b 2O, 24, 

8 b 20-27, 9 a 32-34. 
Mud, thrown up by earthquakes, 

6 a 6. 
Music, harmony in, 6 b l5-l7, 9 a 

Myrtoan Sea, 3 a 30. 

Nature has a liking for contraries, 

6 b 7 . 

Necessity, oi b 8. 
Nemesis, oi b 12. 
Nile, the, 3 b 3i,4 :l i, 2. 
North, pole, 2 a 1-5, 4 b 29 ; wind, 4 b 

20, 28-31, 5 a 3, 4. 
Xotus, 4 b 2i, 31-34, 5 a i. 
Nysa, I a 2i. 

Obscure , the , Heracleitus, 6 b 


Ocean, 3 a 17, b 3, 11. 30. 
Olympus, oo a 7, 1 1 . 
Oracles, 5 b 28. 
Ornithian winds, 5 a 4. 
Orphic Hymn, oi a 28- b 7- 
Ossa, i a 2i. 

Painting, the art of, 6 b 12-15. 
Palace of the Great King, 8 a 15-18. 
Pamphylian Sea, 3 a 30. 
Persia, King of, 8 a 10, 30, b i. 
Persian Gulf, 3 b 3. 
Phaethon, oo a 31. 


Phebol, 3 b i5- 

Pheidias, 9 b 32. 

Philosophy, i a 2, 1 1, b ;. 

Piety towards parents, oo a 34- b 6. 

Pillars of Heracles, 3 a 18, 24, b io, 

23, 32, 4 a i- 
Pits , 2 b 4, 5 b i2. 
Planets, 2 a 13 ff. 
Plato, oi b 24. 

Plurality, unity evolved from, 6 b 5. 
Poles, arctic and antarctic, 2 a 1-5 ; 

north p., 4 b 29 ; south p., 4 b 31. 
Pontus, 3*30, b 24, 25, 27. 
Prayer, attitude of, oo a 17. 
Propitiation, God of, (Zeus), oi a 24. 
Propontis, 3 b I. 
Pry taneum, oo b 1 9. 
Puppet-showman, 8 b 16-19. 
Purification, God of, (Zeus), 01*23. 

Rain, 7 a 33, 9*24, oo a 26 ; Zeus, 
God of r., 01*18; rain-storms, 
2 b io, 4 a 1 6, 27-32 ; rain-winds , 

4 b i9- 

Rainbow, 5 a 30, 32-36, b i. 
Red Sea (Arabian Gulf), 3 b 16, 28. 

Sardinia, 3*13. 

Sardinian Sea, 3*27. 

Saviour, the, (Zeus), oi a 24. 

Scythians, 3 b 8. 

Sea, 2 b 14, 6 b 27, 9*27; phenomena 
occurring in, 6 a 17-27 ; names of 
seas, 3 a i6- b 22. 

Shield of Athena Parthenos, 9 b 35- 

1 Shining Star , the, 2 a 23. 

Shocks, 5 b 33. See also Earth 

Shooting, stars, 5*32; lights, 5 


Shower, 4*31. 

Sicilian sea, 3 a 28. 

Sicily, 3 a 12. 

Similarity evolved from dissimi 
larity, 6 a 5. 

Sky, clear, 4 a 22, 24 ; Zeus, God of 
the Clear Sky, oi u 17. 

Snow, 2 1 io, 4 a 16, 32 b i. 

Society, organization of, 9 b 14-19. 

Sophocles quoted, oo b 25-26. 

South, pole, 2 a 1-5, 4 b 3i; wind, 
4 b 2i, 31-35, 5*1. 

Sporades, 3 a 14. 

Springs, hot, 5 b 24 ; caused by 
earthquakes, 6 a 6, 7. 

Squall, 5 a 5. 

Stars, i b i7, 5 a 36- b i, 8, 7*9, 9*8- 

1 1 , 20, oo a 2 1 ; composed of ether, 
2 a 5; movement of, 2*14, 15; 
names of, 2 a i9ff. ; fixed stars, 
2 a io, n, 23, are unnumbered, 
2 a 1 8 ; planets, 2 a 13 flf. ; shooting 
stars, 5 a 32. 

Steersman, God compared to a, 
oo b 6. 

Storms, 7*23, oo a 9. 

Streaks in the sky, 5 a 31, 35. 

Sun, 2* 29, 5 a 33, b 2, 6 b 27, 7 a 9, 8 b 8, 

9*8, 21, 00*21. 

Supplication, God of, (Zeus), oi a 23. 
Supremacy of God, 7 b 26. 
Susa, 8 a 14, 34. 
Syrian Sea, 3 a 30. 
Syrtes, 3*25. 

Tanais, 3 b 26, 30. 

Taprobane (Ceylon), 3 b 14. 

Thracias, 4 b 30. 

Thunder, 4* 18, 5*11-14 ; perceived 

after lightning, 5* 1 6-21 ; God of 

T.,(Zeus),oi a i7. 
Thunderbolt, 2 b 12, 4 a 18, 5*21-25, 

7*21, oi a i8; God of the T., 

(Zeus), 01* 17. 

Tidal waves, 6 a 18-21, 26, oo a 26. 
Tides affected by the moon, 6*26, 27. 
Time, Zeus is son of, 01* 15. 
Torches , 5 b n. 
Tornado, 5* 7. 
Trade winds, 5* 2. 
Trophies, God of, (Zeus), 01*23. 
Tropics, the, 2 a 12. 

Unity evolved out of plurality, 6 b 5. 

Universe, the, 1*25, 26, 2 b 33, 35; 
its composition, i b 9 ff., 3 a i~4; 
its movement, i b 2o, 24, 7*15,9* 
32-34 ; made up of contrary 
principles, 6*34, b 24, 25 ; organi 
zation of, 9 a i ff. ; God and the 
U., 7 b 9ff, oo b 7 ff; God as creator 
of the U., 7 b 13-24 ; harmony in 
the U., 6 b 23-7 a 5, 9 a i2, 00*4; 
the ordered U., 9*13-14, its 
beauty, 7* 6, its greatness, swift 
ness, radiance, and eternity, 7* 
14-17 ; parent of all things, 7*4, 
IQ ; is spherical, i b 19; its axis. 
i"26; compared, to an army, 
9 b i ff, to a city, 6 b I ff. 

Vengeance, God of, (Zeus), oi a 23. 
Vents, vent-holes in the earth, 5 b 20, 
27, 7 a 32. 


Volcanoes, 5 b 21-23, a 33- 
Vowels, 6 b 1 8. 

Water, element of W., 2 b 3o, 3 a 2, 
6 b 3o, 9 b 24 ; subterranean sources 
of, 5 b 19 ff. See also Moisture. 

Waves, tidal, 6 a 18-21, 26, 00*26. 

West winds, 4 b 2o, 25-28, 5*3. 

Whirlwind, 5*7. 

Whiteness of snow, cause of, 4 a 34, 

Wind, 4*17, b i3, 7 b 2i, 32, 9*24, 
00*9; how caused, 4 b 7-9; blasts 
of, 2 b u, 5*5-8; various types of. 
5*5-16; cloud winds , 4 b i8; 
gulf winds , 4 b 1 5 ; land winds , 
4 b 14 ; * rain winds , 4 b 1 9 ; sub 
terranean winds, 5 b 19 ; names of 
winds : Aparctias 4 b 29, 32, Ape- 
liotes 4 b 23, Argestes 4 b 25, 30, 
Boreas 4 b 20, 28, 29, 5" 3, 4, 
Caecias 4 b 22, 28, 5*1, Circias 
4 b 31, Etesian 5 a 2, Euronotus 
4 b 33, Eurus 4 b 2o, 22, 24, 33, 

lapyx 4 a 26, Libonotus 4 b 34, 
Libophoenix 4 b 34, Lips 4 b 27, 34, 
Notus 4 b 2i, 31-34, 5*1, Olympias 
4 b 26, Ornithian 5 a 4, Thracias 
4 b 30, Zephyrus 4 b 20, 25, 26, 5* 3. 

World, the inhabited, 2 b 2o, 31, 3 a 
10, b i8, 4 b 5 ; its dimensions, 
3 b i8-2i; its divisions, 3 b 22. 

World Below, God of the, (Zeus), 

Writing, the art of, 6 b 18, 

Xerxes, 8 a II, b 4. 

Zen, 01 a 14. 

Zephyrus, 4 b 2O, 25, 26, 5 a 3. 

Zeus, 2 a 25, 9 a 10, 00*19, 01*14; 

etymology of the word, oi a 15 ; 

his various titles, 01* 12-27 ; 

Orphic Hymn describing, 01* 

Zodiac, circle of the, 2 a ii, 12 : 

signs of the, 2* 13. 


J. A. SMITH, M.A., HON. LL.D. (DIN.) 







1. The dignity, usefulness, and difficulty of Psychology. 

2. The opinions of early thinkers about the soul. 

3. Refutation of the view which assigns movement to the soul. 

4. 407 b 27-408* 34. The soul not a harmony. 

408* 34~4o8 b 29. The soul not moved with non-local movement. 
4c8 b 30-5. 4<D9 b 18. The soul not a self-moving number. 

5. 4c9 b 19-411* 7. The soul not composed of elements. 
411*7-23. The soul not present in all things. 

41 i a 24-41 i b 30. The unity of the soul. 


1. First definition of soul. 

2. Second definition of soul. 

3. The faculties of the soul. 

4. The nutritive faculty. 

5. Sense-perception. 

6. The different kinds of sensible object. 

7. Sight and its object. 

8. Hearing and its object. 

9. Smell and its object. 

10. Taste and its object. 

11. Touch and its object. 

12. General characteristics of the external senses. 


1-2. 426 b 7. The number of the external senses. 

2. 426 b 8-427* 16. Common sense. 

3. 427* I7~427 b 26. Thinking, perceiving, and imagining distinguished. 
427 b 27-429*9. Imagination. 

4. Passive mind. 

5. Active mind. 

6. The double operation of mind. 

7. The practical mind, and the difference between it and the 

8. Comparison of mind with sense and with imagination. 

9. Problems about the motive faculty. 

10. II. The cause of the movement of living things. 

12, 13. The mutual relations of the faculties of soul, and their fitness 
for the conditions of life. 


HOLDING as we do that, while knowledge of any kind is 402* 
a thing to be honoured and prized, one kind of it may, either 
by reason of its greater exactness or of a higher dignity and 
greater wonderfulness in its objects, be more honourable 
and precious than another, on both accounts we should 
naturally be led to place in the front rank the study of the 
soul. The knowledge of the soul admittedly contributes 
greatly to the advance of truth in general, and, above all, 5 
to our understanding of Nature, for the soul is in some sense 
the principle of animal life. Our aim is to grasp and under 
stand, first its essential nature, and secondly its properties ; 
of these some are thought to be affections proper to the 
soul itself, while others are considered to attach to the 
animal l owing to the presence within it of soul. 

To attain any assured knowledge about the soul is one 10 
of the most difficult things in the world. As the form of 
question which here presents itself, viz. the question What 
is it ? , recurs in other fields, it might be supposed that there 
was some single method of inquiry applicable to all objects 
whose essential nature we are endeavouring to ascertain (as 15 
there is for derived properties the single method of demon 
stration) ; in that case what we should have to seek for 
would be this unique method. But if there is no such single 
and general method for solving the question of essence, our 
task becomes still more difficult ; in the case of each different 
subject we shall have to determine the appropriate process 
of investigation. If to this there be a clear answer, e.g. 
that the process is demonstration or division, or some 
other known method, difficulties and hesitations still beset ao 
us with what facts shall we begin the inquiry ? For the 
facts which form the starting-points in different subjects 
must be different, as e. g. in the case of numbers and sur 

First, no doubt, it is necessary to determine in which of 
the summa genera soul lies, uhat it is\ is it a this- 
somewhat , a substance, or is it a quale or a quantum, or 
M.e. the complex of soul and body. 

645 19 B 

4 02 a DE ANIMA 

some other of the remaining kinds of predicates which we 

25 have distinguished ? Further, does soul belong to the class 
of potential existents, or is it not rather an actuality ? 
Our answer to this question is of the greatest importance. 
4O2 b We must consider also whether soul is divisible or is with 
out parts, and whether it is everywhere homogeneous or not ; 
and if nothomogeneous, whether its various formsare different 
specifically or generically : up to the present time those who 
have discussed and investigated soul seem to have confined 

5 themselves to the human soul. We must be careful not to ignore 
the question whether soul can be defined in a single unam 
biguous formula, as is the case with animal, or whether we 
must not give a separate formula for each sort of it, as we 
do for horse, dog, man, god (in the latter case the uni 
versal animal and so too every other * common predicate 
being treated eitheras nothing at all or as a later product 1 ). 
Further, if what exists is not a plurality of souls, but a 
plurality of parts of one soul, which ought we to investigate 

10 first, the whole soul or its parts ? (It is also a difficult problem 
to decide which of these parts are in nature distinct from 
one another.) Again, which ought we to investigate first, 
these parts or their functions, mind or thinking, the faculty 
or the act of sensation, and so on? If the investigation of 
the functions precedes that of the parts, the further question 
suggests itself: ought we not before either to consider the 

15 correlative objects, e.g. of sense or thought? 2 It seems not 
only useful for the discovery of the causes of the derived 
properties of substances to be acquainted with the essential 
nature of those substances (as in mathematics it is useful 
for the understanding of the property of the equality of the 

20 interior angles of a triangle to two right angles to know the 
essential nature of the straight and the curved or of the line 
and the plane) but also conversely, for the knowledge of the 
essential nature of a substance is largely promoted by an 
acquaintance with its properties : for, when we are able to 

1 i.e. as presupposing the various sorts instead of being presupposed 
by them. 

2 The text has e.g. the objects of sense or thought before the cor 
responding faculties or parts , but this seems a slip of the author s ; the 
order suggested is object function or operation faculty or part. 

BOOK 1. 1 402 b 

give an account conformable to experience of all or most 
of the properties of a substance, we shall be in the most 
favourable position to say something worth saying about 
the essential nature of that subject ; in all demonstration a 25 
definition of the essence is required as a starting-point,sothat 
definitions which do not enable us to discover the derived 
properties, or which fail to facilitate even a conjecture about 4O3 a 
them, must obviously, one and all, be dialectical and futile. 
A further problem presented by the affections of soul is 
this : are they all affections of the complex of body and 
soul, or is there any one among them peculiar to the soul 
by itself? To determine this is indispensable but difficult. 
If we consider the majority of them, there seems to be no 5 
case in which the soul can act or be acted upon without 
involving the body ; e. g. anger, courage, appetite, and sen 
sation generally. Thinking seems the most probable 
exception ; but if this too proves to be a form of imagina 
tion or to be impossible without imagination, it too requires 
a body as a condition of its existence. If there is any way i 
of acting or being acted upon proper to soul, soul will be 
capable of separate existence ; if there is none, its separate 
existence is impossible. In the latter case, it will be like 
what is straight, which has many properties arising from 
the straightness in it, e.g. that of touching a bronze sphere 
at a point, though straightness divorced from the other con 
stituents of the straight thing cannot touch it in this way ; it 
cannot be so divorced at all, since it is always found in a body. !5 
It therefore 1 seems that all the affections of soul involve a 
body passion, gentleness, fear, pity, courage, joy, loving, 
and hating ; in all these there is a concurrent affection of 
the body. In support of this we may point to the fact that, 
while sometimes on the occasion of violent and striking oc 
currences there is no excitement or fear felt, on others faint 20 
and feeble stimulations produce these emotions, viz. when 
the body is already in a state of tension resembling its con 
dition when we are angry. Here is a still clearer case : in the 
absence of any external cause of terror we find ourselves 
experiencing the feelings of a man in terror. From all this it 

1 Reading drj in 1. 16. 
B 2 

403 a DE ANIMA 

is obvious that the affections of soul are enmattered formu- 
lable essences. 

35 Consequently their definitions ought to correspond, e.g. 
anger should be defined as a certain mode of movement of 
such and such a body (or part or faculty of a body) by 
this or that cause and for this or that end. That is precisely 
why the study of the soul must fall within the science of 
Nature, at least so far as in its affections it manifests this 
double character. Hence a physicist would define an 

30 affection of soul differently from a dialectician; the latter 
would define e.g. anger as the appetite for returning 
pain for pain, or something like that, while the former would 
define it as a boiling of the blood or warm substance sur- 
rounding the heart. The latter assigns the material con 
ditions, the former the form or formulable essence; for what 
he states 1 is the formulable essence of the fact, though for its 
actual existence there must be embodiment of it in a material 
such as is described by the other. Thus the essence of a 
house is assigned in such a formula as a shelter against 
5 destruction by wind, rain, and heat ; the physicist would 
describe it as * stones, bricks, and timbers ; but there is a 
third possible description which would say that it was that 
form in that material with that purpose or end. Which, 
then, among these is entitled to be regarded as the genuine 
physicist ? The one who confines himself to the material, or 
the one who restricts himself to the formulable essence alone? 
Is it not rather the one who combines both in a single for 
mula ? If this is so, how are we to characterize the other two ? 
Must we not say that there is no type of thinker who con 
cerns himself with those qualities or attributes of the material 
which are in fact inseparable from the material, and without 

10 attempting even in thought to separate them? The physicist 
is he who concerns himself with all the properties active and 
passive of bodies or materials thus or thus defined ; attributes 
not considered as being of this character he leaves to others, 
in certain cases it may be to a specialist, e.g. a carpenter or 

1 The reading here adopted in 1. 2 is that of the editio altera of Biehl s 
text (ed. Apeltj viz. ofie, the MS. evidence for which is much superior to 
that for 

BOOK 1. 1 4 o 3 b 

a physician, in others (a) where they are inseparable in fact, 
but are separable from any particular kind of body by an 
effort of abstraction, to the mathematician, (b) where they 15 
are separate both in fact and in thought from body al 
together, to the First Philosopher or metaphysician. But 
we must return from this digression, and repeat that the 
affections of soul are inseparable l from the material sub 
stratum of animal life, to which we have seen that such 
affections, e.g. passion and fear, attach, and have not the 
same mode of being as a line or a plane. 

2 For our study of soul it is necessary, while formulating ao 
the problems of which in our further advance we are to find 
the solutions, to call into council the views of those of our 
predecessors who have declared any opinion on this subject, 
in order that we may profit by whatever is sound in their 
suggestions and avoid their errors. 

The starting-point of our inquiry is an exposition of 
those characteristics which have chiefly been held to belong 
to soul in its very nature. Two characteristic marks have 25 
above all others been recognized as distinguishing that 
which has soul in it from that which has not movement 
and sensation. It may be said that these two are what our 
predecessors have fixed upon as characteristic of soul. 

Some say that what originates movement is both pre 
eminently and primarily soul ; believing that what is not 
itself moved cannot originate movement in another, they 30 
arrived at the view that soul belongs to the class of things 
in movement. This is what led Democritus to say that soul 
is a sort of fire or hot substance ; his forms or atoms are 
infinite in number ; those which are spherical he calls fire 
and soul, and compares them to the motes in the air 
which we see in shafts of light coming through windows ; 
the mixture of seeds of all sorts he calls the elements of the 
whole of Nature (Leucippus gives a similar account) ; the 5 
spherical atoms are identified with soul because atoms of 
that shape are most adapted to permeate everywhere, and 
to set all the others moving by being themselves in move- 
1 Reading in 1. 17, with most MSS., TTJS ^vx 

4<H a DE AN IMA 

ment. This implies the view that soul is identical with what 
produces movement in animals. That is why, further, they 

10 regard respiration as the characteristic mark of life ; as the 
environment compresses the bodies of animals, and tends to 
extrude those atoms which impart movement to them, 
because they themselves are never at rest, there must be a 
reinforcement of these by similar atoms coming in from 
without in the act of respiration ; for they prevent the 
extrusion of those which are already within by counteracting 
the compressing and consolidating force of the environment; 

T 5 and animals continue to live only so long as they are able 
to maintain this resistance. 

The doctrine of the Pythagoreans seems to rest upon the 
same ideas ; some of them declared the motes in air, others 
what moved them, to be soul. These motes were referred 
to because they are seen always in movement, even in a 
complete calm. 

20 The same tendency is shown by those who define soul 
as that which moves itself; all seem to hold the view that 
movement is what is closest to the nature of soul, and that 
while all else is moved by soul, it alone moves itself. This 
belief arises from their never seeing anything originating 
movement which is not first itself moved. 

35 Similarly also Anaxagoras (and whoever agrees with 
him in saying that mind set the whole in movement) de 
clares the moving cause of things to be soul. His position 
must, however, be distinguished from that of Democritus. 
Democritus roundly identifies soul and mind, for he identi 
fies what appears with what is true that is why he com 
mends Homer for the phrase Hector lay with thought 

3 distraught l ; he does not employ mind as a special faculty 

4<H b dealing with truth, but identifies soul and mind. What 

Anaxagoras says about them is more obscure ; in many 

places he tells us that the cause of beauty and order is 

mind, elsewhere that it is soul ; it is found, he says, in all 

? animals, great and small, high and low, but mind (in the 

sense of intelligence) appears not to belong alike to all 

animals, and indeed not even to all human beings. 

1 //. xxiii. 698. 

BOOK 1.2 404 b 

All those, then, who had special regard to the fact that 
what has soul in it is moved, adopted the view that soul 
is to be identified with what is eminently originative of 
movement. All. on the other hand, who looked to the fact 
that what has soul in it knows or perceives what is, iden 
tify soul with the principle or principles of Nature, accord- 10 
ing as they admit several such principles or one only. Thus 
Empedocles declares that it is formed out of all his ele 
ments, each of them also being soul ; his words are : 

For tis by Earth we see Earth, by Water Water, 

By Ether Ether divine, by F*ire destructive Fire, 

By Love Love, and Hate by cruel Hate. 1 5 

In the same way Plato in the Timaeus 2 fashions the soul 
out of his elements ; for like, he holds, is known by like, 
and things are formed out of the principles or elements, so 
that soul must be so too. Similarly also in his lectures On 
Philosophy it was set forth that the Animal-itself is * 
compounded of the Idea itself of the One together with the 
primary length, breadth, and depth, everything else, the 
objects of its perception, being similarly constituted. Again 
he puts his view in yet other terms : Mind is the monad, 
science or knowledge the dyad (because 3 it goes undeviat- 
ingly from one point to another), opinion the number of 
the plane, 4 sensation the number of the solid 5 ; the num 
bers are by him expressly identified with the Forms them 
selves or principles, and are formed out of the elements; 
now things are apprehended either by mind or science or 25 
opinion or sensation, and these same numbers are the 
Forms of things. 

Some thinkers, accepting both premisses, viz. that the 
soul is both originative of movement and cognitive, have 
compounded it of both and declared the soul to be a self- 
moving number. 

As to the nature and number of the first principles 30 
opinions differ. The difference is greatest between those who 
regard them as corporeal and those who regard them as 

1 Fr. 109 Diels. 2 35 Aff. 

3 Like the straight line, whose number is the dyad. 

4 The triad. 8 The tetrad. 

405 a DE AN I MA 

405 a incorporeal, and from both dissent those who make a blend 
and draw their principles from both sources. The number 
of principles is also in dispute ; some admit one only, 
others assert several. There is a consequent diversity in 
their several accounts of soul ; they assume, naturally 
enough, that what is in its own nature originative of 
5 movement must be among what is primordial. That has 
led some to regard it as fire, for fire is the subtlest of 
the elements and nearest to incorporeality ; further, in the 
most primary sense, fire both is moved and originates 
movement in all the others. 

Democritus has expressed himself more ingeniously than 
the rest on the grounds for ascribing each of these two 
characters to soul ; soul and mind are, he says, one and 

TO the same thing, and this thing must be one of the primary 
and indivisible bodies, and its power of originating move 
ment must be due to its fineness of grain and the shape of 
its atoms ; he says that of all the shapes the spherical is 
the most mobile, and that this is the shape of the particles 
of both fire and mind. 

Anaxagoras, as we said above. 1 seems to distinguish 
between soul and mind, but in practice he treats them as 

15 a single substance, except that it is mind that he specially 
po.sits as the principle of all things ; at any rate what he 
says is that mind alone of all that is is simple, unmixed, 
and pure. He assigns both characteristics, knowing and 
origination of movement, to the same principle, when he 
says that it was mind that set the whole in movement. 
Thales, too, to judge from what is recorded about him, 

20 seems to have held soul to be a motive force, since he said 
that the magnet has a soul in it because it moves the iron. 
Diogenes (and others) held the soul to be air because 
he believed air to be finest in grain and a first principle ; 
therein lay the grounds of the soul s powers of knowing 
and originating movement. As the primordial principle 
from which all other things are derived, it is cognitive ; as 
finest in grain, it has the power to originate movement. 

25 Heraclitus too says that the first principle the warm 

1 40 b i-6 

BOOK I. 2 405 

exhalation of which, according to him, everything else is 
composed is soul ; further, that this exhalation is most 
incorporeal and in ceaseless flux ; that what is in movement 
requires that what knows it should be in movement ; and 
that all that is has its being essentially in movement 
(herein agreeing with the majority). 

Alcmaeon also seems to have held a similar view about 
soul ; he says that it is immortal because it resembles the 30 
immortals , and that this immortality belongs to it in 
virtue of its ceaseless movement ; for all the things divine , 
moon, sun, the planets, and the whole heavens, are in 
perpetual movement. 

Of more superficial writers, some, e.g. Hippo, have pro- 4O5 
nounced it to be water ; they seem to have argued from the 
fact that the seed of all animals is fluid, for Hippo tries to 
refute those who say that the soul is blood, on the ground 
that the seed, which is the primordial soul, is not blood. 

Another group (Critias, for example) did hold it to be 5 
blood ; they take perception to be the most characteristic 
attribute of soul, and hold that perceptiveness is due to 
the nature of blood. 

Each of the elements has thus found its partisan, except 
earth earth has found no supporter unless we count as 
such those who have declared soul to be, or to be com- 10 
pounded of, all the elements. All, then, it may be said, 
characterize the soul by three marks, Movement. Sensation, 
Incorporeality, and each of these is traced back to the first 
principles. That is why (with one exception) all those 
who define the soul by its power of knowing make it either 
an element or constructed out of the elements. The 
language they all use is similar ; like, they say, is known 15 
by like ; as the soul knows everything, they construct it 
out of all the principles. Hence all those who admit but 
one cause or element, make the soul also one (e.g. fire 
or air), while those who admit a multiplicity of principles 
make the soul also multiple. The exception is Anaxa- 
goras ; he alone says that mind is impassible and has 20 
nothing in common with anything else. 1 But, if this is so, 

1 Fr. 12. 

4os b DE ANIMA 

how or in virtue of what cause can it know ? That Anaxa- 
goras has not explained, nor can any answer be inferred 
from his words. All who acknowledge pairs of opposites 
among their principles, construct the soul also out of these 
contraries, while those who admit as principles only one con- 

25 trary of each pair, e. g. either hot or cold, likewise make 
the soul some one of these. That is why, also, they allow 
themselves to be guided by the names ; those who identify 
soul with the hot argue that ffjv (to live) is derived from 
(tlv (to boil), while those who identify it with the cold say 
that soul (tyvyri) is so called from the process of respiration 
and refrigeration (Kara^vgis). 

30 Such are the traditional opinions concerning soul, to 
gether with the grounds on which they are maintained. 

We must begin our examination with movement ; for, 3 
doubtless, not only is it false that the essence of soul is cor- 
406* rectly described by those who say that it is what moves (or 
is capable of moving) itself, but it is an impossibility that 
movement should be even an attribute of it. 

We have already 1 pointed out that there is no necessity 
that what originates movement should itself be moved. 
There are two senses in which anything may be moved 
either (a) indirectly, owing to something other than itself, 
5 or (b) directly, owing to itself. Things are indirectly 
moved which are moved as being contained in something 
which is moved, e. g. sailors in a ship, for they are moved in 
a different sense from that in which the ship is moved ; the 
ship is * directly moved , they are indirectly moved , 
because they are in a moving vessel. This is clear if we 
consider their limbs ; the movement proper to the legs (and 
so to man) is walking, and in this case the sailors are not 
10 walking. Recognizing the double sense of * being moved , 
what we have to consider now is whether the soul is directly 
moved and participates in such direct movement. 

There are four species of movement locomotion, altera 
tion, diminution, growth ; consequently if the soul is 
moved, it must be moved with one or several or all of 
1 Phys. viii. 5, esp. 257* 3 1-25 8 b 9. 

BOOK I. 3 4o6 a 

these species of movement. Now if its movement is not 
incidental, there must be a movement natural to it, and, 15 
if so, as all the species enumerated involve place, place 
must be natural to it. But if the essence of soul be to move 
itself, its being moved cannot be incidental to it, as it is 
to what is white or three cubits long ; they too can be 
moved, but only incidentally what is moved is that of 
which white and three cubits long are the attributes, the 
body in which they inhere ; hence they have no place : but ao 
if the soul naturally partakes in movement, it follows that 
it must have a place. 

Further, if there be a movement natural to the soul, 
there must be a counter-movement unnatural to it, and 
conversely. The same applies to rest as well as to move 
ment ; for the terminus ad quern of a thing s natural 
movement is the place of its natural rest, and similarly the 25 
terminus ad quern of its enforced movement is the place of 
its enforced rest. But what meaning can be attached to 
enforced movements or rests of the soul, it is difficult even 
to imagine. 

Further, if the natural movement of the soul be upward, 
the soul must be fire; if downward, it must be earth; 
for upward and downward movements are the definitory 
characteristics of these bodies. The same reasoning applies 
to the intermediate movements, termini, and bodies. 
Further, since the soul is observed to originate movement 30 
in the body, it is reasonable to suppose that it transmits to 
the body the movements by which it itself is moved, and so, 
reversing the order, we may infer from the movements of 
the body back to similar movements of the soul. Now the 4o6 b 
body is moved from place to place with movements of loco 
motion. Hence it would follow that the soul too must in 
accordance with the body change either its place as a whole 
or the relative places of its parts. This carries with it the pos 
sibility that the soul might even quit its body and re-enter it, 
and with this would be involved the possibility of a resurrec 
tion of animals from the dead. But. it may be contended, the 5 
soul can be moved indirectly by somethingelse; for an animal 
can be pushed out of its course. Yes, but that to whose 

4o6 b DE ANIMA 

essence belongs the power of being moved by itself, cannot 
bemoved by something else except incidentally, 1 justaswhat 
is good by or in itself cannot owe its goodness to something 
external to it or to some end to which it is a means. 

10 If the soul is moved, the most probable view is that 
what moves it is sensible things. 2 

We must note also that, if the soul moves itself, it must 
be the mover itself that is moved, so that it follows that 
if movement is in every case a displacement of that which 
is in movement, in that respect in which it is said to be 
moved, the movement of the soul must be a departure from 
its essential nature, at least if its self-movement is essential 
to it, not incidental. 

15 Some go so far as to hold that the movements which the 
soul imparts to the body in which it is are the same in 
kind as those with which it itself is moved. An example 
of this is Democritus, who uses language like that of the 
comic dramatist Philippus, who accounts for the move 
ments that Daedalus imparted to his wooden Aphrodite by 
saying that he poured quicksilver into it ; similarly Demo- 

20 critus says that the spherical atoms which according to him 
constitute soul, owing to their own ceaseless movements 
draw the whole body after them and so produce its move 
ments. We must urge the question whether it is these very 
same atoms which produce rest also how they could do 
so, it is difficult and even impossible to say. And, in 
general, we may object that it is not in this way that the 

25 soul appears to originate movement in animals it is 
through intention or process of thinking. 

It is in the same fashion that the Timaeus* also tries to 
give a physical account of how the soul moves its body ; 
the soul, it is there said, is in movement, and so owing to 
their mutual implication moves the body also. After 
compounding the soul-substance out of the elements and 

1 i.e. so that what is moved is not it but something which goes along 
with it , e.g. a vehicle in which it is contained. 

2 Sc. in which case the movement can only be incidental ; for, as 
we shall see later, it is really the bodily organ of sensation that then is 
* moved . 

3 35 A fT. 

BOOK I. 3 4 o6 b 

dividing it in accordance with the harmonic numbers, in 
order that it may possess a connate sensibility for harmony 30 
and that the whole may move in movements well attuned, 
the Demiurge bent the straight line into a circle ; this single 
circle he divided into two circles united at two common 
points ; one of these he subdivided into seven circles. All this 
implies that the movements of the soul are identified with 
the local movements of the heavens. 

Now, in the first place, it is a mistake to say that the 
soul is a spatial magnitude. It is evident that Plato means 
the soul of the whole to be like the sort of soul which is 
called mind not like the sensitive or the desiderative 5 
soul, for the movements of neither of these are circular. 
Now mind is one and continuous in the sense in which the 
process of thinking is so, and thinking is identical with 
the thoughts which are its parts ; these have a serial unity 
like that of number, not a unity like that of a spatial 
magnitude. Hence mind cannot have that kind of unity 
either ; mind is either without parts or is continuous in some 
other way than that which characterizes a spatial magnitude. 
How, indeed, if it were a spatial magnitude, could mind 10 
possibly think ? Will it think with any one indifferently of 
its parts ? In this case, the part J must be understood either 
in the sense of a spatial magnitude or in the sense of a point 
(if a point can be called a part of a spatial magnitude). If 
we accept the latter alternative, the points being infinite in 
number, obviously the mind can never exhaustively traverse 
them ; if the former, the mind must think the same thing 
over and over again, indeed an infinite number of times 
(whereas it is manifestly possible to think a thing once only). 15 
If contact of any part whatsoever of itself with the object is 
all that is required, why need mind move in a circle, or in 
deed possess magnitude at all? On the other hand, if con 
tact with the whole circle is necessary, what meaning can 
be given to the contact of the parts ? Further, how could 
what has no parts think what has parts, or what has parts 
think what has none ? 1 We must identify the circle referred 
to with mind ; for it is mind whose movement is thinking ao 
1 Sc. but mind in fact thinks or cognizes both. 

4o? a DE ANIMA 

and it is the circle whose movement is revolution, so that if 
thinking is a movement of revolution, the circle which has 
this characteristic movement must be mind. 1 

If the circular movement is eternal, there must be some 
thing which mind is always thinking what can this be? 
For all practical processes of thinking have limits they all 
go on for the sake of something outside the process, and all 
theoretical processes come to a close in the same way as the 
phrases in speech which express processes and results of 
25 thinking. Every such linguistic phrase is either definitory 
or demonstrative. Demonstration has both a starting-point 
and may be said to end in a conclusion or inferred result ; 
even if the process never reaches final completion, at any rate 
it never returns upon itself again to its starting-point, it goes 
on assuming a fresh middle term or a fresh extreme, and 
moves straight forward, but circular movement returns to 
30 its starting-point. Definitions, too, are closed groups of 

Further, if the same revolution is repeated, mind must 
repeatedly think the same object. 

Further, thinking has more resemblance to a coming to 
rest or arrest than to a movement ; the same may be said 
of inferring. 

It might also be urged that what is difficult and enforced 
407 b is incompatible with blessedness ; if the movement of the 
soul is not of its essence, movement of the soul must be 
contrary to its nature. 2 It must also be painful for the soul 
to be inextricably bound up with the body ; nay more, if, 
as is frequently said and widely accepted, it is better for 
mind not to be embodied, the union must be for it undesir 

5 Further, the cause of the revolution of the heavens is left 
obscure. It is not the essence of soul which is the cause of 
this circular movement that movement is only incidental 
to soul nor is, a fortiori , the body its cause. Again, it is 
not even asserted that it is better that soul should be so 
moved ; and yet the reason for which God caused the soul 

1 Omitting vorja-is in 1. 22, with Sophonias and Torstrik. 

2 Sc. and so a hindrance to its bliss . 

BOOK I. 3 4 07 b 

to move in a circle can only have been that movement was 10 
better for it than rest, and movement of this kind better 
than any other. But since this sort of consideration is more 
appropriate to another field of speculation, let us dismiss it 
for the present. 

The view we have just been examining, in company with 
most theories about the soul, involves the following absur 
dity : they all join the soul to a body, or place it in a body, 15 
without adding any specification of the reason of their 
union, or of the bodily conditions required for it. Yet such 
explanation can scarcely be omitted ; for some community 
of nature is presupposed by the fact that the one acts and 
the other is acted upon, the one moves and the other is 
moved ; interaction always implies a special nature in the 
two interagents. All, however, that these thinkers do is to 20 
describe the specific characteristics of the soul ; they do not 
try to determine anything about the body which is to con 
tain it, as if it were possible, as in the Pythagorean myths, 
that any soul could be clothed upon with any body an 
absurd view, for each body seems to have a form and shape 
of its own. It is as absurd as to say that the art of carpentry 
could embody itself in flutes; each art must use its tools, 25 
each soul its body. 

4 There is yet another theory about soul, which has 
commended itself to many as no less probable than any 
of those we have hitherto mentioned, and has rendered 
public account of itself in the court of popular discussion. 30 
Its supporters say that the soul is a kind of harmony, for 

(a) harmony is a blend or composition of contraries, and 

(b) the body is compounded out of contraries. Harmony, 
however, is a certain proportion or composition of the 
constituents blended, and soul can be neither the one nor 
the other of these. Further, the power of originating 
movement cannot belong to a harmony, while almost all 
concur in regarding this as a principal attribute of soul. 

It is more appropriate to call health (or generally one of 408* 
the good states of the body) a harmony than to predicate 
it of the soul. The absurdity becomes most apparent 

4o8 a DE ANIMA 

when we try to attribute the active and passive affections 
of the soul to a harmony ; the necessary readjustment of 

5 their conceptions is difficult. Further, in using the word 
harmony we have one or other of two cases in our mind ; 
the most proper sense is in relation to spatial magnitudes 
which have motion and position, where harmony means 
the disposition and cohesion of their parts in such a 
manner as to prevent the introduction into the whole of 
anything homogeneous with it, and the secondary sense, 
derived from the former, is that in which it means the 
ratio between the constituents so blended ; in neither of 

jo these senses is it plausible to predicate it of soul. That 
soul is a harmony in the sense of the mode of composition 
of the parts of the body is a view easily refutable ; for there 
are many composite parts and those variously compounded ; 
of what bodily part is mind or the sensitive or the appetitive 
faculty the mode of composition ? And what is the mode 
of composition which constitutes each of them ? It is 
equally absurd to identify the soul with the ratio of the 

15 mixture ; for the mixture which makes flesh has a different 
ratio between the elements from that which makes bone. 
The consequence of this view will therefore be that dis 
tributed throughout the whole body there will be many 
souls, since every one of the bodily parts is a different mix 
ture of the elements, and the ratio of mixture is in each 
case a harmony, i. e. a soul. 

From Empedocles at any rate we might demand an 
answer to the following question for he says that each of 
the parts of the body is what it is in virtue of a ratio 

ao between the elements : is the soul identical with this ratio, 
or is it not rather something over and above this which is 
formed in the parts ? Is love the cause of any and every 
mixture, or only of those that are in the right ratio? Is 
love this ratio itself, or is love something over and above 
this ? Such are the problems raised by this account. But, 
on the other hand, if the soul is different from the mixture, 

25 why does it di>appear at one and the same moment with 
that relation between the elements which constitutes flesh or 
the other parts of the animal body ? Further, if the soul 

BOOK I. 4 408* 

is not identical with the ratio of mixture, and it is conse 
quently not the case that each of the parts has a soul, what 
is that which perishes when the soul quits the body ? 

That the soul cannot either be a harmony, or be moved 
in a circle, is clear from what we have said. Yet that it 3 
can be moved incidentally is, as we said above, 1 possible, 
and even that in a sense it can move itself, i. e. in the sense 
that the vehicle in which it is can be moved, and moved by 
it ; in no other sense can the soul be moved in space. 

More legitimate doubts might remain as to its movement 
in view of the following facts. We speak of the soul as being 4o8 b 
pained or pleased, being bold or fearful, being angry, 
perceiving, thinking. All these are regarded as modes of 
movement, and hence it might be inferred that the soul 
is moved. This, however, does not necessarily follow. 
We may admit to the full that being pained or pleased, or 5 
thinking, are movements (each of them a * being moved ), 
and that the movement is originated by the soul. For 
example we may regard anger or fear as such and such 
movements of the heart, and thinking as such and such 
another movement of that organ, or of some other ; these 
modifications may arise either from changes of place in 
certain parts or from qualitative alterations (the.special nature 10 
of the parts and the special modes of their changes being 
for our present purpose irrelevant). Yet to say 2 that it is 
the soul which is angry is as inexact as it would be to say 
that it is the soul that weaves webs or builds houses. It 
is doubtless better to avoid saying that the soul pities or 
learns or thinks and rather to say that it is the man who 
does this with his soul. What we mean is not that the 15 
movement is in the soul, but that sometimes it terminates 
in the soul and sometimes starts from it, sensation e.g. 
coming from without inwards, and reminiscence starting 
from the soul and terminating with the movements, actual 
or residual, in the sense organs. 

The case of mind is different ; it seems to be an inde 
pendent substance implanted within the soul and to be 

1 4o6 a 30 ff , 

2 Reading in 1. II TO fie Xeytti/, with most MSS. and Philoponus. 


4o8 b DE ANIMA 

incapable of being destroyed. If it could be destroyed at 
all, it would be under the blunting influence of old age. 

ao What really happens in respect of mind in old age is, 
however, exactly parallel to what happens in the case of 
the sense organs ; if the old man could recover the proper 
kind of eye, he would see just as well as the young man. 
The incapacity of old age is due to an affection not of the 
soul but of its vehicle, as occurs in drunkenness or disease. 
Thus it is that in old age the activity of mind or intellectual 
apprehension declines only through the decay of some other 

35 inward part ; mind itself is impassible. Thinking, loving, 
and hating are affections not of mind, but of that which 
has mind, so far as it has it. That is why, when this 
vehicle decays, memory and love cease ; they were 
activities not of mind, but of the composite which has 
perished ; mind is, no doubt, something more divine and 

30 impassible. That the soul cannot be moved is therefore 
clear from what we have said, and if it cannot be moved at 
all, manifestly it cannot be moved by itself. 

Of all the opinions we have enumerated, by far the most 
unreasonable is that which declares the soul to be a self- 
moving number ; it involves in the first place all the 
impossibilities which follow from regarding the soul as 
moved, and in the second special absurdities which follow 
4og a from calling it a number. How are we to imagine a unit 
being moved ? By what agency ? What sort of movement 
can be attributed to what is without parts or internal 
differences? If the unit is both originative of movement 
and itself capable of being moved, it must contain difference. 1 
Further, since they say a moving line generates a surface 
5 and a moving point a line, the movements of the psychic 
units must be lines (for a point is a unit having position, 
and the number of the soul is, of course, somewhere and 
has position). 

Again, if from a number a number or a unit is subtracted, 
the remainder is another number ; but plants and many 
animals when divided continue to live, and each segment is 
thought to retain the same kind of soul. 

1 Sc. and so, be no unit . 

BOOK I. 4 409* 

It must be all the same whether we speak of units or ro 
corpuscles ; for if the spherical atoms of Democritus became 
points, nothing being retained but their being a quantum, 
there must remain in each a moving and a moved part, just 
as there is in what is continuous ; what happens has nothing 
to do with the size of the atoms, it depends solely upon 
their being a quantum. That is why there must be some- 15 
thing to originate movement in the units. If in the animal 
what originates movement is the soul, so also must it be in 
the case of the number, so that not the mover and the 
moved together, but the mover only, will be the soul. 
But how is it possible for one of the units to fulfil this 
function of originating movement? There must be some 
difference between such a unit and all the other units, and what 20 
difference can there be between one placed unit and another 
except a difference of position ? If then, on the other hand, 
these psychic units within the body are different from the 
points 0/"the body, there will be two sets of units both occupy 
ing the same place ; for each unit will occupy a point. And 
yet, if there can be two, why cannot there be an infinite 
number ? For if things can occupy an indivisible place, 
they must themselves be indivisible. If, on the other hand, 25 
the points of the body are identical with the units whose 
number is the soul, or if the number of the points in the 
body is the soul, why have not all bodies souls? For 
all bodies contain points or an infinity of points. 

Further, how is it possible for these points to be isolated 
or separated from their bodies, seeing that lines cannot be 30 
resolved into points ? 

5 The result is, as we have said, 1 that this view, while on 
the one side identical with that of those who maintain that 
soul is a subtle kind of body, 2 is on the other entangled in 
the absurdity peculiar to Democritus way of describing 
the manner in which movement is originated by soul. 4og b 
For if the soul is present throughout the whole percipient 
body, there must, if the soul be a kind of body, be two 
bodies in the same place ; and for those who call it a 
1 4o8 b 33 ff. 2 e.g. Heraclitus, and Diogenes of Apollonia. 

C 2 

409 b DE ANIMA 

5 number, there must be many points at one point, or every 
body must have a soul, unless the soul be a different sort of 
number other, that is, than the sum of the points existing 
in a body. Another consequence that follows is that the 
animal must be moved by its number precisely in the way 
that Democritus explained its being moved by his spherical 
psychic atoms. What difference does it make whether we 
speak of small spheres or of large l units, or, quite simply, of 

10 units in movement ? One way or another, the movements of 
the animal must be due to their movements. Hence those 
who combine movement and number in the same subject 
lay themselves open to these and many other similar absurdi 
ties. It is impossible not only that these characters should 
give the definition of soul it is impossible that they should 
even be attributes of it. The point is clear if the attempt 

15 be made to start from this as the account of soul and ex 
plain from it the affections and actions of the soul, e. g. rea 
soning, sensation, pleasure, pain, &c. For, to repeat what 
we have said earlier, 2 movement and number do not facili 
tate even conjecture about the derivative properties of soul. 
Such are the three ways in which soul has traditionally 
been defined ; one group of thinkers declared it to be that 

ao which is most originative of movement because it moves 
itself, another group to be the subtlest and most nearly in 
corporeal of all kinds of body. We have now sufficiently 
set forth the difficulties and inconsistencies to which these 
theories are exposed. It remains now to examine the 
doctrine that soul is composed of the elements. 

The reason assigned for this doctrine is that thus the 
soul may perceive or come to know everything that is, but 

35 the theory necessarily involves itself in many impossibilities. 
Its upholders assume that like is known only by like, and 
imagine that by declaring the soul to be composed of the 
elements they succeed in identifying the soul with all the 
things it is capable of apprehending. But the elements are 
not the only things it knows ; there are many others, or, more 
exactly, an infinite number of others, formed out of the 

30 elements. Let us admit that the soul knows or perceives the 
1 i.e. extended. 8 4O2 b 25-403* 2. 

BOOK I. 5 409* 

elements out of which each of these composites is made up ; 
but by what means will it know or perceive the composite 
whole, e.g. what God, man, flesh, bone (or any other com 
pound) is ? For each is, not merely the elements of which 410* 
it is composed, but those elements combined in a determi 
nate mode or ratio, as Empedocles himself says of bone, 

The kindly Earth in its broad-bosomed moulds l 

Won of clear Water two parts out of eight 5 

And four of Fire ; and so white bones were formed. 

Nothing, therefore, will be gained by the presence of the 
elements in the soul, unless there be also present there 
the various formulae of proportion and the various com 
positions in accordance with them. Each element will 
indeed know its fellow outside, but there will be no know 
ledge of bone or man, unless they too are present in the 
constitution of the soul. The impossibility of this needs no 10 
pointing out ; for who would suggest that stone or man 
could enter into the constitution of the soul ? The same 
applies to the good and the not-good , and so on. 

Further, the word is has many meanings : it may be 
used of a this or substance, or of a quantum, or of a 
quale, or of any other of the kinds of predicates we have 
distinguished. Does the soul consist of all of these or not ? 15 
It does not appear that all have common elements. Is the 
soul formed out of those elements alone which enter into 
substances? If so, how will it be able to know each of the 
other kinds of thing? Will it be said that each kind of 
thing has elements or principles of its own, and that the 
soul is formed out of the whole of these? In that case, 20 
the soul must be a quantum and a quale and a substance. 
But all that can be made out of the elements of a quantum 
is a quantum, not a substance. These (and others like them) 
are the consequences of the view that the soul is composed 
of all the elements. 

It is absurd, also, to say both (a) that like is not capable 
of being affected by like, and (b) that like is perceived or 
known by like, for perceiving, and also both thinking and 25 

1 Burnet broad funnels , fr. 96 Diels. 

4io a DE ANIMA 

knowing, are, on their own assumption, ways of being 
affected or moved. 

There are many puzzles and difficulties raised by saying, 
as Empedocles does, that each set of things is known by 
means of its corporeal elements and by reference to some 
thing in soul which is like them, and additional testimony 

30 is furnished by this new consideration ; for all the parts of 

the animal body which consist wholly of earth such as 

4io b bones, sinews, and hair seem to be wholly insensitive and 

consequently not perceptive even of objects earthy like 

themselves, as they ought to have been. 

Further, each of the principles will have far more ignor 
ance than knowledge, for though each of them will know 
one thing, there will be many of which it will be ignorant. 
Empedocles at any rate must conclude that his God is the 
5 least intelligent of all beings, for of him alone is it true 
that there is one thing, Strife, which he does not know, 
while there is nothing which mortal beings do not know, for 
there is nothing which does not enter into their composition. 
In general, we may ask, Why has not everything a soul, 
since everything either is an element, or is formed out of 
one or several or all of the elements ? Each must certainly 
know one or several or all. 

10 The problem might also be raised, What is that which 
unifies the elements into a soul? The elements correspond, 
it would appear, to the matter ; what unites them, whatever 
it is, is the supremely important factor. But it is impos 
sible that there should be something superior to, and domi 
nant over, the soul (and a fortiori over the mind) ; it is 
reasonable to hold that mind is by nature most primordial 

15 and dominant, while their statement is that it is the ele 
ments which are first of all that is. 

All, both those who assert that the soul, because of its 
knowledge or perception of what is, is compounded out of 
the elements, and those who assert that it is of all things 
the most originative of movement, fail to take into con 
sideration all kinds of soul. In fact (i) not all beings that 
perceive can originate movement ; there appear to be 

20 certain animals which are stationary, and yet local move- 

BOOK I. 5 4io b 

ment is the only one, so it seems, which the soul originates 
in animals. And (2) the same objection holds against all 
those who construct mind and the perceptive faculty out 
of the elements ; for it appears that plants live, and yet 
are not endowed with locomotion or perception, while a 
large number of animals are without discourse of reason. 
Even if these points were waived and mind admitted to be 
a part of the soul (and so too the perceptive faculty), still, 25 
even so, there would be kinds and parts of soul of which 
they had failed to give any account. 

The same objection lies against the view expressed in 
the Orphic poems : there it is said that the soul comes 
in from the whole when breathing takes place, being borne 
in upon the winds. 1 Now this cannot take place in the case 30 
of plants, nor indeed in the case of certain classes of animal, 
for not all classes of animal breathe. This fact has escaped 4 11 * 
the notice of the holders of this view. 

If we must construct the soul out of the elements, there 
is no necessity to suppose that all the elements enter into 
its construction ; one element in each pair of contraries 
will suffice to enable it to know both that element itself 
and its contrary. By means of the straight line we know 5 
both itself and the curved the carpenter s rule enables us 
to test both but what is curved does not enable us to 
distinguish either itself or the straight. 

Certain thinkers say that soul is intermingled in the 
whole universe, and it is perhaps for that reason that Thales 
came to the opinion that all things are full of gods. This 
presents some difficulties : Why does the soul when it re 
sides in air or fire not form an animal, while it does so 10 
when it resides in mixtures of the elements, and that 
although it is held to be of higher quality when contained 
in the former? (One might add the question, why the soul 
in air is maintained to be higher and more immortal than 
that in animals.) Both possible ways of replying to the 
former question lead to absurdity or paradox ; for it is 
beyond paradox to say that fire or air is an animal, and 15 
it is absurd to refuse the name of animal to what has soul 
1 Orpheus, fr. n Diels. 

4ii a DE ANIMA 

in it. The opinion that the elements have soul in them 
seems to have arisen from the doctrine that a whole must 
be homogeneous with its parts. If it is true that animals 
become animate by drawing into themselves a portion of 
what surrounds them, the partisans of this view are bound 
to say that the soul of the Whole too is homogeneous with 
20 all its parts. If the air sucked in is homogeneous, but soul 
heterogeneous, clearly while some part of soul will exist in 
the inbreathed air, some other part will not. The soul 
must either be homogeneous, or such that there are some 
parts of the Whole in which it is not to be found. 

From \\ hat has been said it is now clear that knowing as 
an attribute of soul cannot be explained by soul s being 
35 composed of the elements, and that it is neither sound nor 
true to speak of soul as moved. But since (a) knowing, 
perceiving, opining, and further (b) desiring, wishing, and 
generally all other modes of appetition, belong to soul, 
30 and (c) the local movements of animals, and (d) growth, 
maturity, and decay are produced by the soul, we must 
ask whether each of these is an attribute of the soul as 
4ii b a whole, i. e. whether it is with the whole soul we think, 
perceive, move ourselves, act or are acted upon, or whether 
each of them requires a different part of the soul ? So 
too with regard to life. Does it depend on one of the 
parts of soul ? Or is it dependent on more than one? Or 
on all ? Or has it some quite other cause? 
5 Some hold that the soul is divi>ible, and that one part 
thinks, another desires. If, then, its nature admits of its 
being divided, what can it be that holds the parts to 
gether ? Surely not the body ; on the contrary it seems 
rather to be the soul that holds the body together ; at any 
rate when the soul departs the. body disintegrates and 
decays. If, then, there is something else which makes the 
soul one, this unifying agency would have the best right 
10 to the name of soul, and we shall have to repeat for it the 
question : Is it one or multipartite? If it is one, why not at 
once admit that the soul is one? If it has parts, once 
more the question must be put : What holds its parts 
together, and so ad infinitum ? 

BOOK I. 5 4 n b 

The question might also be raised about the parts of the 
soul : What is the separate role of each in relation to the 
body ? For, if the whole soul holds together the whole 15 
body, we should expect each part of the soul to hold 
together a part of the body. But this seems an impossi 
bility ; it is difficult even to imagine what sort of bodily 
part mind will hold together, or how it will do this. 

It is a fact of observation that plants and certain insects 
go on living when divided into segments ; this means that 20 
each of the segments has a soul in it identical in species, 
though not numerically identical in the different segments, 
for both of the segments for a time possess the power of 
sensation and local movement. That this does not last is 
not surprising, for they no longer possess the organs neces 
sary for self-maintenance. But, all the same, in each of the 
bodily parts there are present all the parts of soul, and the 25 
souls so present are homogeneous with one another and 
with the whole ; this means that the several parts of the 
soul are indisseverable from one another, although the 
whole soul is 1 divisible. It seems also that the principle 
found in plants is also a kind of soul ; for this is the only 
principle which is common to both animals and plants ; 
and this exists in isolation from the principle of sensation, 
though there is nothing which has the latter without the 30 

1 Sc. in a sense, i.e. so as to preserve its homogeneity in even its 
smallest part . 


4i2 a LET the foregoing suffice as our account of the views I 
concerning the soul which have been handed on by our 
predecessors ; let us now dismiss them and make as it were 
a completely fresh start, endeavouring to give a precise 
5 answer to the question, What is soul ? i. e. to formulate the 
most general possible definition of it. 

We are in the habit of recognizing, as one determinate 
kind of what is, substance, and that in several senses, (a) in 
the sense of matter or that which in itself is not a this , 
and (b) in the sense of form or essence, which is that 
precisely in virtue of which a thing is called a this , and 
thirdly (c) in the sense of that which is compounded of both 
10 (a) and (b}. Now matter is potentiality, form actuality ; 
of the latter there are two grades related to one another as 
e. g. knowledge to the exercise of knowledge. 

Among substances are by general consent reckoned 
bodies and especially natural bodies ; for they are the 
principles of all other bodies. Of natural bodies some have 
life in them, others not ; by life we mean self-nutrition 
15 and growth (with its correlative decay). It follows that 
every natural body which has life in it is a substance in 
the sense of a composite. 1 

But since it is also a body of such and such a kind, viz. 
having life, the body cannot be soul ; the body is the 
subject or matter, not what is attributed to it. Hence the 
ao soul must be a substance in the sense of the form of a 
natural body having life potentially within it. But 
substance 2 is actuality, and thus soul is the actuality of 
a body as above characterized. Now the word actuality 
has two senses corresponding respectively to the possession 
of knowledge and the actual exercise of knowledge. It 
is obvious that the soul is actuality in the first sense* 
viz. that of knowledge as possessed, for both sleeping 
25 and waking presuppose the existence of soul, and of these 
waking corresponds to actual knowing, sleeping to know- 

1 i.e. (c) supra. 2 Sc. in the sense of form. 


ledge possessed but not employed, and, in the history 
of the individual, knowledge comes before its employment 
or exercise. 

That is why the soul is the first grade of actuality of a 
natural body having life potentially in it. The body so 
described is a body which is organized. The parts of plants 4i2 b 
in spite of their extreme simplicity are organs ; e. g. the 
leaf serves to shelter the pericarp, the pericarp to shelter 
the fruit, while the roots of plants are analogous to the 
mouth of animals, both serving for the absorption of food. 
If, then, we have to give a general formula applicable to all 
kinds of soul, we must describe it as the first grade of 5 
actuality of a natural organized body. That is why we 
can wholly dismiss as unnecessary the question whether the 
soul and the body are one : it is as meaningless as to ask 
whether the wax and the shape given to it by the stamp 
are one, or generally the matter of a thing and that of 
which it is the matter. Unity has many senses (as many 
as * is has), but the most proper and fundamental sense of 
both is the relation of an actuality to that of \\ hich it is 
the actuality. 

We have now given an answer to the question, What is 10 
soul? an answer which applies to it in its full extent. It 
is substance in the sense which corresponds to the defini 
tive formula of a thing s essence. That means that it 
is 4 the essential whatness of a body of the character just 
assigned. 1 Suppose that what is literally an * organ , 2 like 
an axe, were a natural body, its essential whatness , would 
have been its essence, and so its soul ; if this disappeared 
from it, it would have ceased to be an axe, except in name. 
As it is, 3 it is just an axe ; it wants the character which is 15 
required to make its whatness or formulable essence a 
soul ; for that, it would have had to be a natural body 
of a particular kind, viz. one having in itself the power 
of setting itself in movement and arresting itself. Next, 
apply this doctrine in the case of the * parts of the living 
body. Suppose that the eye were an animal sight would 

1 Viz. organized, or possessed potentially of life. 
8 i.e instrument. s Being an artificial, n< 

not a natural, body. 

4i2 b DE ANIMA 

have been its soul, for sight is the substance or essence of 
ao the eye which corresponds to the formula, 1 the eyebeing merely 
the matter of seeing ; 2 when seeing is removed the eye is 
no longer an eye, except in name it is no more a real eye 
than the eye of a statue or of a painted figure. We must 
now extend our consideration from the parts to the 
whole living body; for what the departmental sense is to 
the bodily part which is its organ, that the whole faculty 
of sense is to the whole sensitive body as such. 
25 We must not understand by that which is potentially 
capable of living what has lost the soul it had, but only 
what still retains it ; but seeds and fruits are bodies which 
possess the qualification. 3 Consequently, while waking is 
actuality in a sense corresponding to the cutting and the 
4i3 a seeing, 4 the soul is actuality in the sense corresponding to 
the power of sight and the power in the tool; 5 the body 
corresponds to what exists in potentiality ; as the pupil 
plus the power of sight constitutes the eye, so the soul plus 
the body constitutes the animal. 

From this it indubitably follows that the soul is insepar 
able from its body, or at any rate that certain parts of it are 
5 (if it has parts) for the actuality of some of them is nothing 
but the actualities of their bodily parts. Yet some may be 
separable because they are not the actualities of any body 
at all. Further, we have no light on the problem whether 
the soul may not be the actuality of its body in the sense 
in which the sailor is the actuality 6 of the ship. 

This must suffice as our sketch or outlinedetermination 
10 of the nature of soul. 

Since what is clear or logically more evident emerges from 2 

what in itself is confused but more observable by us, we 

must reconsider our results from this point of view. For it 

is not enough for a definitive formula to express as most 

i 5 now do the mere fact; it must include and exhibit the ground 

1 i.e. which states what it is to be an eye. 

2 Punctuating in 1. 20 \6/ov (6 8 ... o\//-f<ur), ^?, with By water. 

3 Though only potentially, i.e. they are at a further remove from 
actuality than the fully formed and organized body. 

4 i.e. to the second grade of actuality. 

8 i.e. to the first grade of actuality. i.e. actuator. 

BOOK II. a 413* 

also. At present definitions are given in a form analogous 
to the conclusion of a syllogism ; e. g. What is squaring ? 
The construction of an equilateral rectangle equal to a given 
oblong rectangle. Such a definition is in form equivalent 
to a conclusion. 1 One that tells us that squaring is the 
discovery of a line which is a mean proportional between 
the two unequal sides of the given rectangle discloses the 
ground of what is defined. 

We resume our inquiry from a fresh starting-point by 20 
calling attention to the fact that what has soul in it differs 
from what has not. in that the former displays life. Now this 
word has more than one sense, and provided any one alone 
of these is found in a thing we say that thing is living. 
Living, that is, may mean thinking or perception or local 
movement and rest, or movement in the sense of nutrition, 
decay, and growth. Hence we think of plants also as living, 35 
for they are observed to possess in themselves an originative 
power through which they increase or decrease in all spatial 
directions ; they grow up and down, and everything that 
grows increases its bulk alike in both directions or indeed in 
all, and continues to live so long as it can absorb nutii- 30 

This power of self-nutrition can be isolated from the other 
powers mentioned, but not they from it in mortal beings 
at least. The fact is obvious in plants ; for it is the only 
psychic power they possess. 

This is the originative power the possession of which leads 4i3 b 
us to speak of things as living at all, but it is the possession 
of sensation that leads us for the first time to speak of living 
things as animals ; for even those beings which possess no 
power of local movement but do possess the power of 
sensation we call animals and not merely living things. 

The primary form of sense is touch, which belongs to all 
animals. Just as the power of self-nutrition can be isolated 5 
from touch and sensation generally, so touch can be iso 
lated from all other forms of sense. (By the power of self- 
nutrition we mean that departmental power of the soul 
which is common to plants and animals : all animals 
1 i.e. it has nothing in it corresponding to a middle term. 

4i3 b DE ANIMA 

whatsoever are observed to have the sense of touch.) What 

10 the explanation of these two facts is, we must discuss later. 1 
At present we must confine ourselves to saying that soul is 
the source of these phenomena and is characterized by them, 
viz. by the powers of self-nutrition, sensation, thinking, 
and motivity. 

Is each of these a soul or a part of a soul ? And if a part, 
a part in what sense? A part merely distinguishable by 

15 definition or a part distinct in local situation as well ? In the 
case of certain of these powers, the answers to these ques 
tions are easy, in the case of others we are puzzled what to 
say. Just as in the case of plants which when divided are 
observed to continue to live though removed to a distance 
from one another (thus showing that in their case the soul 
of each individual plant before division was actually one, 
potentially many), so we notice a similar result in other 

ao varieties of soul, i.e. in insects which have been cut in two ; 
each of the segments possesses both sensation and local 
movement ; and if sensation, necessarily also imagination 
and appetition ; for, where there is sensation, there is also 
pleasure and pain, and, where these, necessarily also 

We have no evidence as yet about mind or the power to 

35 think ; it seems to be a widely different kind of soul, differ 
ing as what is eternal from what is perishable ; it alone is 
capable of existence in isolation from all other psychic 
powers. All the other parts of soul, it is evident from what 
we have said, are, in spite of certain statements to the con 
trary, incapable of separate existence though, of course, 
distinguishable by definition. If opining is distinct from per- 

3 ceiving, to be capable of opining and to be capable of per 
ceiving must be distinct, and so with all the other forms of 
living above enumerated. Further, some animals possess all 
these parts of soul, some certain of them only, others one only 
(this is what enables us to classify animals) ; the cause must 
414* be considered later. 2 A similar arrangement is found also with 
in the field of the senses ; some classes of animals have all 

1 iii. 12, esp. 434* 22-30, b io ff. 2 iii. 12, 13. 

BOOK II. 2 414* 

the senses, some only certain of them, others only one, the 
most indispensable, touch. 

Since the expression that whereby we live and perceive 
has two meanings, just like the expression that whereby we 5 
know that may mean either (a) knowledge or (b) the soul, 
for we can speak of knowing by or with either, and 
similarly that whereby we are in health may be either 1 
(a) health or (b) the body or some part of the body ; and 
since of the two terms thus contrasted knowledge or health 
is the name of a form, essence, or ratio, or if we so express 
it an actuality of a recipient matter knowledge of what is 10 
capable of knowing, health of what is capable of being 
made healthy 2 (for the operation of that which is capable 
of originating change terminates and has its seat in what is 
changed or altered) ; further, since it is the soul by or with 
which primarily we live, perceive, and think : it follows that 
the soul must be a ratio or formulable essence, not a matter 
or subject. For, as we said, 3 the word substance has three 
meanings form, matter, and the complex of both and of 15 
these three what is called matter is potentiality, what is 
called form actuality. Since then the complex here is the 
living thing, the body cannot be the actuality of the soul; it 
js the soul which is the actuality of a certain kind of body. 
Hence the Tightness of the view that the soul cannot be with 
out a body, while it cannot be a body ; it is not a body but 20 
something relative to a body. That is why it is in a body, and 
a body of a definite kind. It was a mistake, therefore, to do as 
former thinkers did, merely to fit it into a body without 
adding a definite specification of the kind or character of that 
body. Reflection confirms the observed fact ; the actuality of 35 
any given thing can only be realized in what is already poten 
tially that thing, i.e. in a matter of its own appropriate to it. 
From all this it follows that soul is an actuality or formu 
lable essence of something that possesses a potentiality 
of being besouled. 

1 Omitting in 1. 7, with Bywater. 

2 The reading vyuurrov (in 1. 10) is better than vytnoriKoi). As be 

tween the two forms the MS. evidence is of little if any value. 

4i4 a DE ANIMA 

Of the psychic powers above enumerated 1 some kinds of 3 
living things, as we have said, 2 possess all, some less than all, 

30 others one only. Those we have mentioned are the nutri 
tive, the appetitive, the sensory, the locomotive, and the 
power of thinking. Plants have none but the first, the 
nutritive, while another order of living things has this plus 
4i4 b the sensory. If any order of living things has the 
sensory, it must also have the appetitive ; for appetite is 
the genus of which desire, passion, and wish are the 
species ; now all animals have one sense at least, viz. 
touch, and whatever has a sense has the capacity for 
pleasure and pain and therefore has pleasant and painful 
objects present to it, and wherever these are present, there 
5 is desire, for desire is just appetition of what is pleasant. 
Further, all animals have the sense for food (for touch is 
the sense for food) ; the food of all living things consists 
of what is dry, moist, hot, cold, and these are the qualities 
apprehended by touch; all other sensible qualities are 

10 apprehended by touch only indirectly. Sounds, colours, 
and odours contribute nothing to nutriment ; flavours fall 
within the field of tangible qualities. Hunger and thirst are 
forms of desire, hunger a desire for what is dry and hot, 
thirst a desire for what is cold and moist ; flavour is a 
sort of seasoning added to both. We must later 3 clear up 

15 these points, but at present it may be enough to say that all 
animals that possess the sense of touch have also appeti 
tion. The case of imagination is obscure ; we must examine 
it later. 4 Certain kinds of animals possess in addition the 
power of locomotion, and still another order of animate 
beings, i.e. man and possibly another order like man or 

20 superior to him, the power of thinking, i.e. mind. It is 
now evident that a single definition can be given of 
soul only in the same sense as one can be given of figure. 
For, as in that case there is no figure distinguishable and 
apart from triangle, &c., so here there is no soul apart from 
the forms of soul just enumerated. It is true that a highly 
general definition can be given for figure which will fit all 

1 4i3 a 23-5> b n-i3, 21-4. 2 4i3 b 32-414* I- 

3 c. 1 1. iii. 12. 434 b \%-2i,De Sensu 4. 4 iii. 3, II. 433 b 3 I ~434 a 7. 

BOOK II. 3 4*4 b 

figures without expressing the peculiar nature of any 
figure. So here in the case of soul and its specific forms. 
Hence it is absurd in this and similar cases to demand an 35 
absolutely general definition, which will fail to express the 
peculiar nature of anything that is, or again, omitting this, 
to look for separate definitions corresponding to each 
infima species. The cases of figure and soul are exactly 
parallel ; for the particulars subsumed under the com 
mon name in both cases figures and living beings 
constitute a series, each successive term of which 30 
potentially contains its predecessor, e.g. the square the 
triangle, the sensory power the self-nutritive. Hence we 
must ask in the case of each order of living things, What is 
its soul, i.e. What is the soul of plant, animal, man? Why 
the terms are related in this serial way must form the sub 
ject of later examination. 1 But the facts are that the power 415* 
of perception is never found apart from the power of self- 
nutrition, while in plants the latter is found isolated from 
the former. Again, no sense is found apart from that of 
touch, while touch is found by itself; many animals have 5 
neither sight, hearing, nor smell. Again, among living 
things that possess sense some have the power of loco 
motion, some not. Lastly, certain living beings a small 
minority possess calculation and thought, for (among 
mortal beings) those which possess calculation have all the 
other powers above mentioned, while the converse does not 10 
hold indeed some live by imagination alone, while others 
have not even imagination. The mind that knows with 
immediate intuition presents a different problem. 2 

It is evident that the way to give the most adequate 
definition of soul is to seek in the case of each of its forms for 
the most appropriate definition. 

4 It is necessary for the student of these forms of soul first 
to find a definition of each, expressive of what it is, and 15 
then to investigate its derivative properties, &c. But if we 
are to express what each is, viz. what the thinking power 
is, or the perceptive, or the nutritive, we must go farther 

1 iii. 12, 13. 2 Cf. iii. 4-8. 

45-19 D 

4i5 a DE ANIMA 

back and first give an account of thinking or perceiving, 
for in the order of investigation the question of what an 
agent does precedes the question, what enables it to do what 

20 it does. If this is correct, we must on the same ground go 
yet another step farther back and have some clear view of 
the objects of each ; thus we must start with these objects, 
e.g. with food, with what is perceptible, or with what is 

It follows that first of all we must treat of nutrition and 
reproduction, 1 for the nutritive soul is found along with 
all the others and is the most primitive and widely distributed 
power of soul, being indeed that one in virtue of which all 

25 are said to have life. The acts in which it manifests itself 
are reproduction and the use of food reproduction, I 
say, because for any living thing that has reached its normal 
development and which is unmutilated, and whose mode of 
generation is not spontaneous, the most natural act is the pro 
duction of another like itself, an animal producing an animal, 
a plant a plant, in order that, as far as its nature allows, it 
4i5 b may partake in the eternal and divine. That is the goal 
towards which all things strive, that for the sake of which 
they do whatsoever their nature renders possible. The 
phrase for the sake of which is ambiguous ; it may mean 
either (a) the end to achieve which, or (b) the being in whose 
interest, the act is done. Since then no living thing is able 
to partake in what is eternal and divine by uninterrupted 
continuance (for nothing perishable can for ever remain one 
5 and the same), it tries to achieve that end in the only way 
possible to it, and success is possible in varying degrees ; 
so it remains not indeed as the self-same individual but 
continues its existence in something like itself not numeri 
cally but specifically one. 2 

The soul is the cause or source of the living body. 
The terms cause and source have many senses. But the 
soul is the cause of its body alike in all three senses which 

10 we explicitly recognize. It is (a) the source or origin of 

1 Sc. which we shall see to be inseparable from nutrition . 

2 There is an unbroken current of the same specific life flowing 
through a discontinuous series of individual beings of the same species 
united by descent. 

BOOK II. 4 4i5 b 

movement, it is (b) the end, it is (c) the essence of the 
whole living body. 

That it is the last, is clear ; for in everything the essence 
is identical with the ground of its being, and here, in the 
case of living things, their being is to live, and of their being 
and their living the soul in them is the cause or source. 
Further, the actuality of whatever is potential is identical 
with its formulable essence. 

It is manifest that the soul is also the final cause of its 15 
body. For Nature, like mind, always does whatever it does 
for the sake of something, which something is its end. To 
that something corresponds in the case of animals the soul 
,and in this it follows the order of nature ; all natural bodies 
are organs of the soul. This is true of those that enter 
into the constitution of plants as well as of those which 
enter into that of animals. This shows that that for the 
sake of which they are is soul. We must here recall the two 2 <> 
sensesof that for the sake of which , viz, (a) the end to achieve 
which, and (b) the being in whose interest, anything is or is 

We must maintain, further, that the soul is also the 
cause of the living body as the original source of local 
movement. The power of locomotion is not found, however, 
in all living things. But change of quality and change of 
quantity are also due to the soul. Sensation is held to be 
a qualitative alteration, and nothing except what has soul 
in it is capable of sensation. The same holds of the quan- 25 
titative changes which constitute growth and decay; nothing 
grows or decays naturally 1 except what feeds itself, and 
nothing feeds itself except what has a share of soul in it. 

Empedocles is wrong in adding that growth in plants is 
to be explained, the downward rooting by the natural tend 
ency of earth to travel downwards, and the upward branching 4i6 a 
by the similar natural tendency of fire to travel upwards. 
For he misinterprets up and down ; up and down are not 
for all things what they are for the whole Cosmos : if we 
are to distinguish and identify organs according to their 
functions, the roots of plants are analogous to the head in 5 
1 i.e. of itself. 
D 2 

4 i6 a DE ANIMA 

animals. Further, we must ask what is the force that holds 
together the earth and the fire which tend to travel in 
contrary directions ; if there is no counteracting force, they 
will be torn asunder ; if there is, this must be the soul and 
the cause of nutrition and growth. By some the element 
of fire is held to be the cause of nutrition and growth, 

10 for it alone of the primary bodies or elements is observed 
to feed and increase itself. Hence the suggestion that in 
both plants and animals it is it which is the operative force. 
A concurrent cause in a sense it certainly is, but not the 

15 principal cause ; that is rather the soul ; for while the 
growth of fire goes on without limit so long as there is 
a supply of fuel, in the case of all complex wholes formed in 
the course of nature there is a limit or ratio which deter 
mines their size and increase, and limit and ratio are marks 
of soul but not of fire, and belong to the side of formulable 
essence rather than that of matter. 

Nutrition and reproduction are due to one and the same 
psychic power. It is necessary first to give precision to our 

20 account of food, for it is by this function of absorbing food 
that this psychic power is distinguished from all the others. 
The current view is that what serves as food to a living 
thing is what is contrary to it not that in every pair of 
contraries each is food to the other : to be food a contrary 
must not only be transformable into the other and vice versa, 
it must also in so doing increase the bulk of the other. 
Many a contrary is transformed into its other and vice versa, 
where neither is even a quantum and so cannot increase in 

25 bulk, e.g. an invalid into a healthy subject. It is clear that 
not even those contraries which satisfy both the conditions 
mentioned above are food to one another in precisely the 
same sense ; water may be said to feed fire, but not fire 
water. Where the members of the pair are elementary bodies 
only one of the contraries, it would appear, can be said to 
feed the other. But there is a difficulty here. One set of 

30 thinkers assert that like is fed, as well as increased in 
amount, by like. Another set, as we have said, maintain 
the very reverse, viz. that what feeds and what is fed are 
contrary to one another ; like, they argue, is incapable of 

BOOK II. 4 4i6 

being affected by like ; but food is changed in the process 
of digestion, and change is always to what is opposite or to 
what is intermediate. Further, food is acted upon by 35 
what is nourished by it, not the other way round, as timber 
is worked by a carpenter and not conversely ; there is a 
change in the carpenter but it is merely a change from not- 
working to working. In answering this problem it makes 
all the difference whether we mean by the food the finished 
or the * raw product. If we use the word food of both, viz. 
of the completely undigested and the completely digested 
matter, we can justify both the rival accounts of it ; taking 5 
food in the sense of undigested matter, it is the contrary of 
what is fed by it, taking it as digested it is like what is fed 
by it. Consequently it is clear that in a certain sense we may 
say that both parties are right, both wrong. 

Since nothing except what is alive can be fed, what is 
fed is the besouled body and just because it has soul in it. 
Hence food is essentially related to what has soul in it. 10 
Food has a power which is other than the power to increase 
the bulk of what is fed by it ; so far forth as what has soul 
in it is a quantum, food may increase its quantity, but it is 
only so far as what has soul in it is a this-somewhat or 
substance that food acts as food ; in that case it maintains 
the being of what is fed, and that continues to be what it is 
so long as the process of nutrition continues. Further, it is 15 
the agent in generation, i.e. not the generation of the indi 
vidual fed but the reproduction of another like it ; the 
substance of the individual fed is already in existence ; 
the existence of no substance is a self-generation but only 
a self-maintenance. 

Hence the psychic power which we are now studying 
may be described as that which tends to maintain whatever 
has this power in it of continuing such as it was, and food 
helps it to do its work. That is why, if deprived of food, " 
it must cease to be. 

The process of nutrition involves three factors, (a) what 20 
is fed, (b) that wherewith it is fed, (c) what does the feeding 
of these (c) is the first soul, 1 (a) the body which has that 
1 i.e. the earliest and most indispensable kind of soul. 

4i6 b DE AN I MA 

soul in it, (b) the food. But since it is right to call things 
after the ends they realize, and the end of this soul is to 
generate another being like that in which it is, the first soul 
35 ought to be named the reproductive soul. The expression 
(b) wherewith it is fed is ambiguous just as is the expression 
wherewith the ship is steered ; that may mean either (i) 
the hand or (ii) the rudder, i.e. either (i) what is moved 
and sets in movement, or (ii) what is merely moved. We 
can apply this analogy here if we recall that all food must 
be capable of being digested, and that what produces diges 
tion is warmth ; that is why everything that has soul in it 
possesses warmth. 

We have now given an outline account of the nature of 
food ; further details must be given in the appropriate 
place. 1 

Having made these distinctions let us now speak of 5 
sensation in the widest sense. Sensation depends, as we 
have said, 2 on a process of movement or affection from 
without, for it is held to be some sort of change of quality. 
35 Now some thinkers assert that like is affected only by like; 
4 1 ? in what sense this is possible and in what sense impossible, 
we have explained in our general discussion of acting and 
being acted upon. 3 

Here arises a problem : why do we not perceive the senses 
themselves 4 as well as the external objects of sense, or why 
without the stimulation of external objects do they not 
produce sensation, seeing that they contain in themselves 
5 fire, earth, and all the other elements, which are the 
direct or indirect objects of sense? It is clear that what 
is sensitive is so only potentially, not actually. The 
power of sense is parallel to what is combustible, for that 
never ignites itself spontaneously, but requires an agent 
which has the power of starting ignition; otherwise it could 
have set itself on fire, and would not have needed actual 
fire to set it ablaze. 

1 In a lost (or never written) work On Nutrition or On Increase 
and Nutrition; cf.Bonitz, Index lO4 b 16-28. 

2 41 5 b 24, cf. 4io a 25. 3 De Gen. et Corr. 323 b 18 ff. 
4 This probably means the sensoria. 

BOOK II.5 417* 

In reply we must recall that we use the word perceive 
in two ways, for we say (a) that what has the power to 10 
hear or see, * sees or hears , even though it is at the 
moment asleep, and also (b) that what is actually seeing or 
hearing, * sees or hears . Hence sense too must have 
two meanings, sense potential, and sense actual. Similarly 
to be a sentient means either (a) to have a certain power or 
(b) to manifest a certain activity. To begin with, for a time, 
let us speak as if there were no difference between (i) being 15 
moved or affected, and (ii) being active, for movement is a 
kind of activity an imperfect kind, as has elsewhere been 
explained. 1 Everything that is acted upon or moved is acted 
upon by an agent which is actually at work. Hence it is 
that in one sense, as has already been stated, 2 what acts and 
what is acted upon are like, in another unlike, i. e. prior to and ao 
during the change the two factors are unlike, after it like. 

But we must now distinguish not only betivcen what is 
potential and what is actual but also different senses in 
which things can be said to be potential or actual ; up to 
now we have been speaking as if each of these phrases had 
only one sense. We can speak of something as a knower 
either (a) as when we say that man is a knower, meaning 
that man falls within the class of beings that know or have 
knowledge, or (b) as when we are speaking of a man who 35 
possesses a knowledge of grammar ; each of these is so 
called as having in him a certain potentiality, but there is a 
difference between their respective potentialities, the one 
(a) being a potential knower, because his kind or matter is 
such and such, the other (b}, because he can in the absence 
of any external counteracting cause realize his knowledge 
in actual knowing at will. This implies a third meaning of 
a knower (c), one who is already realizing his knowledge 
he is a knower in actuality and in the most proper sense 
is knowing, e. g. this A. 3 Both the former are potential 30 
knowers, who realize their respective potentialities, the one 
(a) by change of quality, i. e. repeated transitions from one 

3 i.e. this individual item of grammatical knowledge, e.g. that the 1st 
person singular of the perfect indicative active of Auoo ends in -a. 

4i7 a DE ANIMA 

state to its opposite 1 under instruction, the other (b) by the 
4 1 ? transition from the inactive possession of sense or grammar 
to their active exercise. The two kinds of transition are 

Also the expression to be acted upon has more than 
one meaning; it may mean either (a) the extinction of one 
of two contraries by the other, or (b) the maintenance of 
what is potential by the agency of what is actual and already 
like what is acted upon, with such likeness as is compatible 

5 with one s being actual and the other potential. For what 
possesses knowledge becomes an actual knower by a transi 
tion which is either not an alteration of it at all (being in 
reality a development into its true self or actuality) or at 
least an alteration in a quite different sense from the usual 

Hence it is wrong to speak of a wise man as being 
altered when he uses his wisdom, just as it would be absurd 
to speak of a builder as being altered when..he is using his 
skill in building a house. 

10 What in the case of knowing or understanding leads from 
potentiality to actuality ought not to be called teaching 2 
but something else. That which starting with the power 
to know learns or acquires knowledge through the agency 
of one who actually knows and has the power of teaching 
either (a) ought not to be said to be acted upon at all or 

15 (b) we must recognize two senses of alteration, viz. (i) the 
substitution of one quality tor another, the first being the 
contrary of the second, or (ii) the development of an existent 
quality from potentiality in the direction of fixity or nature. 
In the case of what is to possess sense, the first tran>ition 
is due to the action of the male parent and takes place before 
birth so th it at birth the living thing is, in respect of sen 
sation, at the stage which corresponds to the possession of 
knowledge. Actual sensation corresponds to the stage of 
the exercise of knowledge. But between the two cases 

30 compared there is a difference; the objects that excite the 
sensory powers to activity, the seen, the heard, &c., are out- 

1 viz. from ignorance or error to knowledge or truth. 

2 It would have been clearer had he said learning . 

BOOK II. 5 4i7 b 

side. The ground of this difference is that what actual 
sensation apprehends is individuals, while what knowledge 
apprehends is universals, and these are in a sense within 
the soul. That is why a man can exercise his knowledge 
when he wishes, but his sensation does not depend upon 
himself a sensible object must be there. A similar 25 
statement must be made about our knoivledge of what is 
sensible on the same ground, viz. that the sensible objects 
are individual and external. 

A later more appropriate occasion may be found 1 
thoroughly to clear up all this. At present it must be 30 
enough to recognize the distinctions already drawn ; a thing 
may be said to be potential in either of two senses, (a) in 
the sense in which we might say of a boy that he may 
become a general or (b) in the sense in which we might say 
the same of an adult, and there are two corresponding senses 
of the term a potential sentient . There are no separate 4i8 a 
names for the two stages of potentiality; we have pointed out 
that they are different and how they are different. We can 
not help using the incorrect terms being acted upon or 
altered of the two transitions involved. As we have said, 2 
what has the power of sensation is potentially like what 
the perceived object is actually ; that is, while at the beginning 
of the process of its being acted upon the two interacting 
factors are dissimilar, at the end the one acted upon is 5 
assimilated to the other and is identical in quality with it. 

6 In dealing with each of the senses we shall have first to 
speak of the objects which are perceptible by each. The 
term object of sense covers three kinds of objects, two 
kinds of which are, in our language, directly perceptible, 
while the remaining one is only incidentally perceptible. Of 
the first two kinds one (a) consists of what is perceptible 
by a single sense, the other (b) of what is perceptible by any 10 
and all of the senses. 3 I call by the name of special 
object of this or that sense that which cannot be perceived 
by any other sense than that one and in respect of which no 

1 iii. 4, 5- 2 4i? a 12-20. 

3 Really, it is enough if it is perceptible by more than one sense. 

4i8 a DE ANIMA 

error is possible ; in this sense colour is the special object 
of sight, sound of hearing, flavour of taste. Touch, 
indeed, discriminates more than one set of different qualities. 

15 Each sense has one kind of object which it discerns, and 
never errs in reporting that what is before it is colour or 
sound (though it may err as to what it is that is coloured 
or where that is, or what it is that is sounding or where that 
is). Such objects are what we propose to call the special 
objects of this or that sense. 

Common sensibles are movement, rest, number, figure, 
magnitude ; these are not peculiar to any one sense, but are 
common to all. There are at any rate certain kinds of 
movement which are perceptible both by touch and by 

ao We speak of an incidental object of sense where e. g. the 
white object which we see is the son of Diares ; here 
because being the son of Diares is incidental to the directly 
visible white patch we speak of the son of Diares as being 
(incidentally) perceived or seen by us. Because this is 
only incidentally an object of sense, it in no way as such 
affects the senses. Of the two former kinds, both of which 
are in their own nature perceptible by sense, the first kind 
that of special objects of the several senses constitute 

35 the objects of sense in the strictest sense of the term and it 
is to them that in the nature of things the structure of 
each several sense is adapted. 

The object of sight is the visible, and what is visible is 7 
(a) colour and (b) a certain kind of object which can be 
described in words but which has no single name ; what 
we mean by (b) will be abundantly clear as we proceed. 
Whatever is visible is colour and colour is what lies upon 
30 what is in its own nature visible ; in its own nature here 
means not that visibility is involved in the definition of 
what thus underlies colour, but that that substratum 
contains in itself the cause of visibility. Every colour has 
in it the power to set in movement what is actually trans- 
4i8 b parent ; that power constitutes its very nature. That is 
why it is not visible except with the help of light ; it 

BOOK II. 7 4i8 b 

is only in light that the colour of a thing is seen. Hence 
our first task is to explain what light is. 

Now there clearly is something which is transparent, 
and by transparent I mean what is visible, and yet not ? 
visible in itself, but rather owing its visibility to the colour 
of something else; of this character are air, water, and 
many solid bodies. Neither air nor water is transparent 
because it is air or water ; they are transparent because 
each of them has contained in it a certain substance which is 
the same in both and is also found in the eternal body 
which constitutes the uppermost shell of the physical 
Cosmos. Of this substance light is the activity the 
activity of what is transparent so far forth as it has in it 
the determinate power of becoming transparent ; where 10 
this power is present, there is also the potentiality of the 
contrary, viz. darkness. Light is as it were the proper 
colour of what is transparent, and exists whenever the 
potentially transparent is excited to actuality by the 
influence of fire or something resembling the uppermost 
body ; for fire too contains something which is one and 
the same with the substance in question. 

We have now explained what the transparent is and 
what light is; light is neither fire nor any kind whatsoever 
of body nor an efflux from any kind of body (if it were, it 15 
would again itself be a kind of body) it is the presence of 
fire or something resembling fire in what is transparent. 
It is certainly not a body, for two bodies cannot be present 
in the same place. The opposite of light is darkness ; 
darkness is the absence from what is transparent of the 
corresponding positive state above characterized ; clearly 
therefore, light is just the presence of that. 

Empedocles (and with him all others who used the same 30 
forms of expression) was wrong in speaking of light as 
travelling or being at a given moment between the earth 
and its envelope, its movement being unobservable by us ; 
that view is contrary both to the clear evidence of argument 
and to the observed facts ; if the distance traversed were 
short, the movement might have been unobservable, but where 35 
the distance is from extreme East to extreme West, the 
draught upon our powers of belief is too great. 

4i8 b DE ANIMA 

What is capable of taking on colour is what in itself is 
colourless, as what can take on sound is what is soundless; 
what is colourless includes (a) what is transparent and (b) 
what is invisible or scarcely visible, i. e. what is dark . 

30 The latter (b) is the same as what is transparent, when it is 
potentially, not of course when it is actually transparent ; 
it is the same substance which is now darkness, now 

4i9 a Not everything that is visible depends upon light for its 
visibility. This is only true of the proper colour of things. 
Some objects of sight which in light are invisible, in 
darkness stimulate the sense ; that is, things that appear 
fiery or shining. This class of objects has no simple 

5 common name, but instances of it are fungi, flesh, 1 heads, 
scales, and eyes of fish. In none of these is what is seen their 
own proper 1 colour. Why we see these at all is another 
question. At present what is obvious is that what is seen 
in light is always colour. That is why without the help of 
light colour remains invisible. Its being colour at all 

10 means precisely its having in it the power to set in move 
ment what is already actually transparent, and, as we 
have seen, the actuality of what is transparent is just 

The following experiment makes the necessity of a 
medium clear. If what has colour is placed in immediate 
contact with the eye, it cannot be seen. Colour sets in 
movement not the sense organ but what is transparent, 
e.g. the air, and that, extending continuously from the 

15 object of the organ, sets the latter in movement. Demo- 
critus misrepresents the facts when he expresses the 
opinion that if the interspace were empty one could dis 
tinctly see an ant on the vault of the sky ; that is an impos 
sibility. Seeing is due to an affection or change of what has 
the perceptive faculty, and it cannot be affected by the seen 
colour itself; it remains that it must be affected by what 
comes between. Hence it is indispensable that there be 

ao something in between if there were nothing, so far from 

1 Reading Kpfns in 1. 5 with Chandler. In fact flesh is, and horn is 
not, an instance of the class. 

BOOK II. 7 4 i9 a 

seeing with greater distinctness, we should see nothing at 

We have now explained the cause why colour cannot be 
seen otherwise than in light. Fire on the other hand is seen 
both in darkness and in light ; this double possibility 
follows necessarily from our theory, for it is just fire 
that makes what is potentially transparent actually trans 

The same account holds also of sound and smell ; if 25 
the object of either of these senses is in immediate contact 
with the organ no sensation is produced. In both cases 
the object sets in movement only what lies between, and 
this in turn sets the organ in movement : if what sounds or 
smells is brought into immediate contact with the organ, 
no sensation will be produced. The same, in spite of all 30 
appearances, applies also to touch and taste ; \vhy there is 
this apparent difference will be clear later. 1 What comes 
between in the case of sounds is air ; the corresponding 
medium in the case of smell has no name. But, corre 
sponding to what is transparent in the case of colour, there 
is a quality found both in air and water, which serves as 
a medium for what has smell I say in water 1 because 35 
animals that live in water as well as those that live on land 
seem to possess the sense of smell, and in air because 4iQ b 
man and all other land animals that breathe, perceive smells 
only when they breathe air in. The explanation of this 
too will be given later. 2 

8 Now let us, to begin with, make certain distinctions about 
sound and hearing. 

Sound may mean either of two things (a) actual, and 5 
(b) potential, sound. There are certain things which, as 
we say, l have no sound , e. g. sponges or wool, others which 
have, e. g. bronze and in general all things which are smooth 
and solid the latter are said to have a sound because they 
can make a sound, i. e. can generate actual sound between 
themselves and the organ of hearing. 

Actual sound requires for its occurrence (i, ii) two such 
1 422 b 34 ff. 2 42i b 13-422* 6. 

4ig b DE ANIMA 

10 bodies and (iii) a space between them; for it is generated 
by an impact. Hence it is impossible for one body only to 
generate a sound there must be a body impinging and a 
body impinged upon ; what sounds does so by striking 
against something else, and this is impossible without a 
movement from place to place. 

As we have said, not all bodies can by impact on one 
another produce sound ; impact on wool makes no sound, 

15 while the impact on bronze or any body which is smooth 
and hollow does. Bronze gives out a sound when struck 
because it is smooth ; bodies which are hollow owing to 
reflection repeat the original impact over and over again, 
the body originally set in movement being unable to escape 
from the concavity. 

Further, we must remark that sound is heard both in air 
and in water, though less distinctly in the latter. Yet 
neither air nor water is the principal cause of sound. 

20 What is required for the production of sound is an impact 
of two solids against one another and against the air. The 
latter condition is satisfied when the air impinged upon 
does not retreat before the blow, i. e. is not dissipated by it. 
That is why it must be struck with a sudden sharp blow, 
if it is to sound the movement of the whip must outrun 
the dispersion of the air, just as one might get in a stroke 
at a heap or whirl of sand as it was travelling rapidly past. 

25 An echo occurs, when, a mass of air having been unified, 
bounded, and prevented from dissipation by the containing 
walls of a vessel, the air originally struck by the impinging 
body and set in movement by it rebounds from this mass 
of air like a ball from a wall. It is probable that in all 
generation of sound echo takes place, though it is frequently 
only indistinctly heard. What happens here must be 
analogous to what happens in the case of light ; light is 

30 always reflected otherwise it would not be diffused and 
outside what was directly illuminated by the sun there 
would be blank darkness ; but this reflected light is not 
always strong enough, as it is when it is reflected from water, 
bronze, and other smooth bodies, to cast a shadow, which 
is the distinguishing mark by which we recognize light. 

BOOK II. 8 4i9 b 

It is rightly said that an empty space plays the chief 
part in the production of hearing, for what people mean by 
the vacuum is the air, which is what causes hearing, 
when that air is set in movement as one continuous mass ; 
but owing to its friability it emits no sound, being dissipated 35 
by impinging upon any surface which is not smooth. When 420* 
the surface on which it impinges is quite smooth, what is 
produced by the original impact is a united mass, a result 
due to the smoothness of the surface with which the air is 
in contact at the other end. 

What has the power of producing sound is what has the 
power of setting in movement a single mass of air which 
is continuous from the impinging body up to the organ of 
hearing. The organ of hearing is physically united with 
air, 1 and because it is in air, the air inside is moved con 
currently with the air outside. Hence animals do not hear 5 
with all parts of their bodies, nor do all parts admit of the 
entrance of air ; for even the part which can be moved and 
cansound has not air everywhere in it. 2 Air in itself is, owing 
to its friability, quite soundless ; only when its dissipation 
is prevented is its movement sound. The air in the car 
is built into a chamber just to prevent this dissipating 
movement, in order that the animal may accurately appre- 10 
hend all varieties of the movements of the air outside. 
That is why we hear also in water, viz. because the water 
cannot get into the air chamber or even, owing to the 
spirals, into the outer ear. If this does happen, hearing ceases, 
as it also does if the tympanic membrane is damaged, 
just as sight ceases if the membrane covering the pupil is 
damaged. It is also a test of deafness whether the ear does 15 
or does not reverberate like a horn; the air inside the ear has 
always a movement of its own, but the sound we hear is 
always the sounding of something else, not of the organ 
itself. That is why we say that we hear with what is empty 
and echoes, viz. because what we hear with is a chamber 
which contains a bounded mass of air. 

1 i.e. it has air incorporated in its structure. 

2 Reading iptyofyov in 1. 7 : the required air is localized not only in the 
body but in the ear. 

43o a DE ANIMA 

Which is it that sounds , the striking body or the struck ? 

ao Is not the answer it is both, but each in a different way ? 
Sound is a movement of what can rebound from a smooth 
surface when struck against it. As we have explained l not 
everything sounds when it strikes or is struck, e.g. if one 
needle is struck against another, neither emits any sound. 

25 In order, therefore, that sound may be generated, what is 
struck must be smooth, to enable the air to rebound and be 
shaken off from it in one piece. 

The distinctions between different sounding bodies show 
themselves only in actual sound ; 2 as without the help of 
light colours remain invisible, so without the help of actual 
sound the distinctions between acute and grave sounds 
remain inaudible. Acute and grave are here metaphors, 
transferred from their proper sphere, viz. that of touch, 

30 where they mean respectively (a) what moves the sense 
much in a short time, (b) what moves the sense little in a 
long time. Not that what is sharp really moves fast, and 
what is grave, slowly, but that the difference in the qualities 
of the one and the other movement is due to their respective 
42O b speeds. There seems to be a sort of parallelism between 
what is acute or ^rave to hearing and what is sharp or 
blunt to touch ; what is sharp as it were stabs, while what 
is blunt pushes, the one producing its effect in a short, the 
other in a long time, so that the one is quick, the other 

5 Let the foregoing suffice as an analysis of sound. Voice 
is a kind of sound characteristic of what has soul in it ; 
nothing that is without soul utters voice, it being only by 
a metaphor that we speak of the voice of the flute or the lyre 
or generally of what (being without soul) possesses the 
power of producing a succession of notes which differ in 
length and pitch and timbre. The metaphor is based on 
the fact that all these differences are found also in voice. 
Many animals are voiceless, e.g. all non-sanguineous animals 

10 and among sanguineous animals fish. This is just what we 
should expect, since voice is a certain movement of air. 

1 4i9 b 6, 13. 

2 i. e. when these bodies, e.g. the strings of a lyre, are actually sounding. 

BOOK II. 8 420 b 

The fish, like those in the Achelous, which are said to have 
voice, really make the sounds with their gills or some 
similar organ. Voice is the sound made by an animal, and 
that with a special organ. As we saw, everything that 
makes a sound does so by the impact of something (a) against 
something ehe, (b] across a space, (c) filled with air; hence 15 
it is only to be expected that no animals utter voice except 
those which take in air. Once air is inbreathed, Nature 
uses it for two different purposes, as the tongue is used both 
for tasting and for articulating; in that case of the two 
functions tasting is necessary for the animal s existence 
(hence it is found more widely distributed), while articulate 
speech is a luxury subserving its possessor s well-being; 
similarly in the former case Nature employs the breath 20 
both as an indispensable means to the regulation of the 
inner temperature of the living body and also as the matter 
of articulate voice, in the interests of its possessor s well- 
being. Why its former use is indispensable must be 
discussed elsewhere. 1 

The organ of respiration is the windpipe, and the organ 
to which this is related as means to end is the lungs. The 
latter is the part of the body by which the temperature of 
land animals is raised above that of all others. But what 25 
primarily requires the air drawn in by respiration is not 
only this but the region surrounding the heart. That is 
why when animals bieathe the air must penetrate inwards. 

Voice then is the impact of the inbreathed air against 
the windpipe , and the agent that produces the impact is 
the soul resident in these parts of the body. Not every 
sound, as we said, made by an animal is voice (even with 30 
the tongue we may merely make a sound which is not 
voice, or without the tongue as in coughing) ; what produces 
the impact must have soul in it and must be accompanied 
by an net of imagination, for voice is a sound with a 
meaning, and is not merely the result of any impact of the 
breath as in coughing ; in voice the breath in the windpipe 
is used as an instrument to knock with against the walls of 
the windpipe. This is confirmed by our inability to speak 421 
1 De Resp. 478** 28 ; P. A. 642* 3i- b 4. 

645-19 E 

42i a DE ANIMA 

when we are breathing either out or in we can only do so 
by holding our breath ; we make the movements with the 
breath so checked. It is clear also why fish are voiceless ; 
they have no windpipe. And they have no windpipe 
5 because they do not breathe or take in air. Why they do 
not is a question belonging to another inquiry. 1 

Smell and its object are much less easy to determine 9 
than what we have hitherto discussed ; the distinguishing 
characteristic of the object of smell is less obvious than 
those of sound or colour. The ground of this is that our 
power of smell is less discriminating and in general inferior 

10 to that of many species of animals ; men have a poor sense 
of smell and our apprehension of its proper objects is inse 
parably bound up with and so confused by pleasure and 
pain, which shows that in us the organ is inaccurate. It is 
probable that there is a parallel failure in the perception 
of colour by animals that have hard eyes: probably they 
discriminate differences of colour only by the presence or 

15 absence of what excites fear, and that it is thus that human 
beings distinguish smells. It seems that there is an analogy 
between smell and taste, and that the species of tastes 
run parallel to those of smells the only difference being 
that our sense of taste is more discriminating than our sense 
of smell, because the former is a modification of touch, 
which reaches in man the maximum of discriminative 

ao accuracy. While in respect of all the other senses we fall 
below many species of animals, in respect of touch we far 
excel all other species in exactness of discrimination. That 
is why man is the most intelligent of all animals. This is 
confirmed by the fact that it is to differences in the organ 
of touch and to nothing else that the differences between 
man and man in respect of natural endowment are due ; 

25 men whose flesh is hard are ill-endowed by nature, men whose 
flesh is soft, well-endowed. 

As flavours may be divided into (a) sweet, (b) bitter, so 
with smells. In some things the flavour and the smell have 
the same quality, i.e. both are sweet or both bitter, in others 
1 Cf. De Resp. 474** 25-9, 476 a 6-15 ; P. A. 669* 2-5. 

BOOK II. 9 42i a 

they diverge. Similarly a smell, like a flavour, may be 
pungent, astringent, acid, or succulent. But, as we said, 30 
because smells are much less easy to discriminate than 
flavours, the names of these varieties are applied to smells 
only metaphorically ; for example sweet is extended from 42i b 
the taste to the smell of saffron or honey, * pungent to that 
of thyme, and so on. 1 

In the same sense in which hearing has for its object 
both the audible and the inaudible, sight both the visible 5 
and the invisible, smell has for its object both the odorous 
and the inodorous. Inodorous may be either (a) what 
has no smell at all, or (b) what has a small or feeble smell. 
The same ambiguity lurks in the word * tasteless . 

Smelling, like the operation of the senses previously 
examined, takes place through a medium, i.e. through air 
or water I add water, because water-animals too (both 10 
sanguineous and non-sanguineous) seem to smell just as 
much as land-animals ; at any rate some of them make 
directly for their food from a distance if it has any scent. 
That is why the following facts constitute a problem for us. 
All animals smell in the same way, but man smells only 
when he inhales ; if he exhales or holds his breath, he ceases 
to smell, no difference being made whether the odorous 15 
object is distant or near, or even placed inside the nose and 
actually on the wall of the nostril ; it is a disability common 
to all the senses not to perceive what is in immediate contact 
with the organ of sense, but our failure to apprehend what 
is odorous without the help of inhalation is peculiar (the 
fact is obvious on making the experiment). Now since 
bloodless animals do not breathe, they must, it might be 2 
argued, have some novel sense not reckoned among the 
usual five. Our reply must be that this is impossible, 
since it is scent that is perceived ; a sense that apprehends 
what is odorous and what has a good or bad odour cannot 
be anything but smell. Further, they are observed to be 
deleteriously effected by the same strong odours as man is, 
e.g. bitumen, sulphur, and the like. These animals must 35 

1 Because of the felt likeness between the respective smells and the 
really sweet or pungent tastes of the same herbs, c. 

E a 

42i b DE ANIMA 

be able to smell without being able to breathe. The prob 
able explanation is that in man the organ of smell has a 
certain superiority over that in all other animals just as his 
eyes have over those of hard-eyed animals. Man s eyes have 
in the eyelids a kind of shelter or envelope, which must be 
30 shifted or drawn back in order that we may see, while hard- 
eyed animals have nothing of the kind, but at once see 
whatever presents itself in the transparent medium. Simi 
larly in certain species of animals the organ of smell is like 
422* the eye of hard-eyed animals, uncurtained, while in others 
which take in air it probably has a curtain over it, which 
is drawn back in inhalation, owing to the dilating of the 
veins or pores. } That explains also why such animals cannot 
5 smell under water ; to smell they must first inhale, and that 
they cannot do under water. 

Smells come from what is dry as flavours from what is 
moist. Consequently the organ of smell is potentially dry. 

What can be tasted is always something that can be 10 
touched, and just for that reason it cannot be perceived 
through an interposed foreign body, for touch means the 

10 absence of any intervening body. Further, the flavoured 
and tastcable body is suspended in a liquid matter, and this 
is tangible. Hence, if we lived in water, we should perceive 
a sweet object introduced into the water, but the water 
would not be the medium through which we perceived; 
our perception would be due to the solution of the sweet 
substance in what we imbibed, just as if it were mixed with 
some drink. There is no parallel here to the perception of 
colour, which is due neither to any blending of anything 
with anything, nor to any efflux of anything from anything. 

15 In the case of taste, there is nothing corresponding to the 
medium in the case of the senses previously discussed ; 
but as the object of sight is colour, so the object of taste 
is flavour. But nothing excites a perception of flavour 
without the help of liquid ; what acts upon the sense of 
taste must be either actually or potentially liquid like what 
is saline ; it must be both (a) itself easily dissolved, and (b) 

20 capable of dissolving along with itself the tongue. Taste 

BOOK II. 10 422* 

apprehends both (a) what has taste and (b) what has no 
taste, if we mean by (b) what has only a slight or feeble 
flavour or what tends to destroy the sense of taste. In this 
it is exactly parallel to sight, which apprehends both what 
is visible and what is invisible (for darkness is invisible and 
yet is discriminated by sight ; so is, in a different way, what 
is over-brilliant), and to hearing, which apprehends both 
sound and silence, of which the one is audible and the other 
inaudible, and also over-loud sound. This corresponds in 35 
the case of hearing to over-bright light in the case of sight. 
As a faint sound is inaudible , so in a sense is a loud or 
violent sound. The word invisible and similar privative 
terms cover not only (a) what is simply without some power, 
but also (b) what is adapted by nature to have it but has 
not it or has it only in a very low degree, as when we say 
that a species of swallow is footless or that a variety of 
fruit is stoneless - 1 So too taste has as its object both 
what can be tasted and the tasteless the latter in the sense 30 
of what has little flavour or a bad flavour or one destructive 
of taste. The difference between what is tasteless and 
what is not seems to rest ultimately on that between what 
is drinkable and what is undrinkable both are tasteable, 
but the latter is bad and tends to destroy taste, while the 
former is the normal stimulus of taste. What is drinkable 
is the common object of both touch and taste. 

Since what can be tasted is liquid, the organ for its per- 422 b 
ception cannot be either (a} actually liquid or (b) incapable 
of becoming liquid. Tasting means a being affected by 2 
what can be tasted as such ; hence the organ of taste must 
be liquefied, and so to start with must be non-liquid but 
capable of liquefaction without loss of its distinctive nature. 
This is confirmed by the fact that the tongue cannot taste 5 
either when it is too dry or when it is too moist ; in the 
latter case what occurs is due to a contact with the pre- 
existent moisture in the tongue itself, when after a foretaste 
of some strong flavour we try to taste another flavour ; it is 
in this way that sick persons find everything they taste 

1 Cf. Hist. An. 48; b 24-29 and Frag. 267 R. 

2 Sc. * and so, as we have seen, a being assimilated to . 

422 b DE ANIMA 

bitter, viz. because, when they taste, their tongues are over 
flowing with bitter moisture. 

* The species of flavour are, as in the case of colour, (a) 
simple, i.e. the two contraries, the sweet and the bitter, (b) 
secondary, viz. (i) on the side of the sweet, the succulent, 
(ii) on the side of the bitter, the saline, (iii) between 
these come the pungent, the harsh, the astringent, and the 
acid ; these pretty well exhaust the varieties of flavour. 

15 It follows that what has the power of tasting is what is 
potentially of that kind, and that what is tasteable is what 
has the power of making it actually what it itself already is. 

Whatever can be said of what is tangible, can be said of n 
touch, and vice versa ; if touch is not a single sense but a 
group of senses, there must be several kinds of what is 
tangible. It is a problem whether touch is a single sense 

20 or a group of senses. It is also a problem, what is the 
organ of touch ; is it or is it not the flesh (including what 
in certain animals is homologous with flesh) ? On the 
second view, flesh is the medium of touch, the real organ 
being situated farther inward. The problem arises because 
the field of each sense is according to the accepted view 
determined as the range between a single pair of contraries? 
white and black for sight, acute and grave for hearing, 

25 bitter and sweet for taste ; but in the field of what is 
tangible we find several such pairs, hot cold, dry moist, 
hard soft, &c. This problem finds a partial solution, when it 
is recalled that in the case of the other senses more than one 
pair of contraries are to be met with, e. g. in sound not only 

3 acute and grave but loud and soft, smooth and rough, 
&c.; there are similar contrasts in the field of colour. Never 
theless we are unable clearly to detect in the case of touch 
what the single subject is which underlies the contrasted 
qualities and corresponds to sound in the case of hearing. 
To the question whether the organ of touch lies inward 
or not (i.e. whether we need look any farther than the flesh), 
4 2 3 a no indication in favour of the second answer can be drawn 
from the fact that if the object comes into contact with the 
flesh it is at once perceived. For even under present 

BOOK II. ii 423 a 

conditions if the experiment is made of making a web and 
stretching it tight over the flesh, as soon as this web is 
touched the sensation is reported in the same manner as 
before, yet it is clear that the organ is not in this membrane. 
If the membrane could be grown on to the flesh, the report 5 
would travel still quicker. The flesh plays in touch very 
much the same part as would be played in the other 
senses by an air-envelope growing round our body ; had we 
such an envelope attached to us we should have supposed 
that it was by a single organ that we perceived sounds, 
colours, and smells, and we should have taken sight, hearing, 
and smell to be a single sense. But as it is, because that Io 
through which the different movements are transmitted is 
not naturally attached to our bodies, the difference of the 
various sense-organs is too plain to miss. But in the case 
of touch the obscurity remains. 

There must be such a naturally attached medium as 
flesh, for no living body could be constructed of air or 
water ; it must be something solid. Consequently it must 
be composed of earth along with these, which is just what 
flesh and its analogue in animals which have no true flesh 
tend to be. Hence of necessity the medium through which 15 
are transmitted the manifoldly contrasted tactual qualities 
must be a body naturally attached to the organism. That 
they are manifold is clear when we consider touching with 
the tongue ; we apprehend at the tongue all tangible quali 
ties as well as flavour. Suppose all the rest of our flesh was, 
like the tongue, sensitive to flavour, we should have identi 
fied the sense of taste and the sense of touch ; what ao 
saves us from this identification is the fact that touch and 
taste are not always found together in the same part of the 
body. The following problem might be raised. Let us 
assume that every body has depth, i.e. has three dimensions, 
and that if two bodies have a third body between them 
they cannot be in contact with one another ; let us remember 
that what is liquid is a body and must be or contain water, 25 
and that if two bodies touch one another under water, 
their touching surfaces cannot be dry, but must have water 
between, viz. the water which wets their bounding surfaces ; 

4 23 B DE ANIMA 

from all this it follows that in water two bodies cannot be 
in contact with one another. The same holds of two bodies 
in air air being to bodies in air precisely what water is to 
30 bodies in water but the facts are not so evident to our 
observation, because we live in air, just as animals that live 
in water would not notice that the things which touch one 
another in water have wet surfaces. The problem, then, is : 
does the perception of all objects of sense take place in the 
same way, or does it not, e.g. taste and touch requiring 
contact (as they are commonly thought to do), while all 
other senses perceive over a distance ? The distinction 

5 is unsound ; we perceive what is hard or soft, as well 
as the objects of hearing, sight, and smell, through a 
medium , only that the latter are perceived over a greater 
distance th-in the former ; that is why the facts escape our 
notice. For we do perceive everything through a medium; 
but in these cases the fact escapes us. Yet, to repeat what 
we said before, if the medium for touch were a membrane 
separating us from the object without our observing its 

10 existence, we should be relatively to it in the same condition 
as we are now to air or water in which we are immersed ; 
in their case we fancy we can touch objects, nothing coming in 
between us and them. But there remains this difference 
between what can be touched and what can be seen or can 
sound ; in the latter two cases we perceive because the 
medium produces a certain effect upon us, whereas in the 
perception of objects of touch we are affected not by but 

15 along with the medium ; it is as if a man were struck through 
his shield, where the shock is not first given to th shield 
and passed on to the man, but the concussion of both is 
simultaneous. 1 

In general, flesh and the tongue are related to the real 
organs of touch and taste, as air and water are to those of 

20 sight, hearing, and smell. Hence in neither the one case nor 

1 As, according to Aristotle, transmission through atnftftummay be 
timeless, the fact that there is no interval of time between the shock 
to the shield and ihat to the body behind it, would not show that the 
medium in touch was in any way different from that of any oi the other 
senses. (V. Baeumker, Problem der Materie, pp. 5 5, 56.) The difference 
is that in touch what is affected is in effect a single continuous body. 

BOOK II. II 4*3 b 

the other can there be any perception of an object if it is 
placed immediately upon the organ, e.g. if a white object is 
placed on the surface of the eye. This again shows that what 
has the p >wer of perceiving the tangible is seated inside. 
Only so would there be a complete analogy with all the other 
senses. In their case if you place the object on the organ 
it is not perceived, here if you place it on the flesh it is 35 
perceived ; therefore flesh is not the organ but the medium 
of touch. 

What can be touched are distinctive qualities of body as 
body; by such differences I mean those which characterize 
the elements, viz. hot cold, dry moist, of which we have 
spoken earlier in our treatise on the elements. 1 The organ 30 
for the perception of these is that of touch that part of 
the body in which primarily the sense of touch resides. 
This is that part which is potentially such as its object is 
actually : for all sense-perception is a process of being so 
affected ; so that that which makes something such as it itself 424*" 
actually is makes the other such because the other is already 
potentially such. That is why when an object of touch is 
equally hot and cold or hard and soft we cannot perceive ; 
what we perceive must have a degree of the sensible quality 
lying beyond the neutral point. This implies that the sense 
itself is a mean 2 between any two opposite qualities which 
determine the field of that sense. It is to this that it owes its 5 
power of discerning the objects in that field. What is * in the 
middle is fitted to discern; relatively to either extreme it 
can put itself in the place of the other. As what is to 
perceive both white and black must, to begin with, be actually 
neither but potentially either (and so with all the other 
sense-organs), so the organ of touch must be neither hot 
nor cold. 

Further, as in a sense sight had 3 for its object both 10 

1 De Gen. et Corr. ii. 2, 3. 

24 The Mean is what possesses any two contrasting qualities in 
equipoise ; what is so placed may be so related to more than one pair 
of contraries. In general, each pair determines the range or field of 
one sense, at the extremities of which they lie while the Mean occupies 
the centre, but more than one pair may be found within the same field, 
the Mean being equally central to all of them. 

8 422* 20 ff. 

44 a DE ANIMA 

what was visible and what was invisible (and there was a 
parallel truth about all the other senses discussed), 1 so touch 
has for its object both what is tangible and what is intangible. 
Here by intangible is meant (a) what like air possesses 
some quality of tangible things in a very slight degree and 
(b) what possesses it in an excessive degree, as destructive 
things do. 

15 We have now given an outline account of each of the several 

The following results applying to any and every sense 12 
may now be formulated. 

(A) By a sense is meant what has the power of receiving 
into itself the sensible forms of things without the matter. 
This must be conceived of as taking place in the way in 
which a piece of wax takes on the impress of a signet-ring 

ao without the iron or gold; we say that what produces 
the impression is a signet of bronze or gold, but its parti 
cular metallic constitution makes no difference : in a similar 
way the sense is affected by what is coloured or flavoured 
or sounding, but it is indifferent what in each case the 
substance is ; what alone matters is what quality it has, i.e. 
in what ratio its constituents are combined. 2 

(B) By an organ of sense is meant that in which 
ultimately such a power is seated. 

25 The sense and its organ are the same in fact, but their 
essence is not the same. What perceives is, of course, a 
spatial magnitude, but we must not admit that either the 
having the power to perceive or the sense itself is a mag 
nitude ; what they are is a certain ratio 3 or power in a 

42 1 b 3-6, 422 a 29. 

2 In any case of the action of one body X on another Y it is the form 
of X that acts and the result is the presence in Fof a form identical 
with that of X, which is therefore taken on by Y without the matter 
which in X accompanied it. The peculiarity in the case of a sense 
(not clearly indicated here) is that the form so induced is not present 
in Y in the same way as it is in a merely physical or inanimate 
body. This is brought out by St. Thomas in his commentary on the 

5 The word here translated ratio is the word which elsewhere I 
have rendered formulable essence ; it is declared by Aristotle to be 
synonymous with form . It must not be regarded as identical with 
the mere numerical proportion between the material ingredients or 

BOOK II. 12 424 a 

magnitude. This enables us to explain why objects of 
sense which possess one of two opposite sensible qualities in 
a degree largely in excess of the other opposite destroy the 
organs of sense ; if the movement set up by an object is too 30 
strong for the organ, the equipoise of contrary qualities in 
the organ, which just is its sensory power, is disturbed ; it 
is precisely as concord and tone are destroyed by too 
violently twanging the strings of a lyre. This explains also 
why plants cannot perceive, in spite of their having a portion 
of soul in them and obviously being affected by tangible 
objects themselves; for undoubtedly their temperature can 
be lowered or raised. The explanation is that they have no 4 2 4 b 
mean of contrary qualities, and so no principle in them cap 
able of taking on the forms of sensible objects without 
their matter; in the case of plants the affection is an affection 
by form-and-matter together. The problem might be raised : 
Can what cannot smell be said to be affected by smells or 
what cannot see by colours, and so on ? It might be said that 5 
a smell is just what can be smelt, and if it produces any 
effect it Can only be so as to make something smell it, and 
it might be argued that what cannot smell cannot be 
affected by smells and further that what can smell can be 
affected by it only in so far as it has in it the power to smell 
(similarly with the proper objects of all the other senses). 
Indeed that this is so is made quite evident as follows. 
Light or darkness, sounds and smells leave bodies quite 10 
unaffected ; what does affect bodies is not these but the 
bodies which are their vehicles, e. g. what splits the trunk of 
a tree is not the sound of the thunder but the air which accom 
panies thunder. Yes, but, it may be objected, bodies are 
affected by what is tangible and by flavours. If not, by 
what are things that are without soul affected, i. e. altered 
in quality ? Must we not, then, admit that the objects of the 
other senses also may affect them ? Is not the true account 

constituents of the organ : it is at least what the Schoolmen called 
forma operans and is here expressly identified with the force or power 
incorporated in the organ, which when evoked by the stimulating agency 
of the external object manifests itselt as the apprehension or discrimina 
tion of the objective quality inwardized by the process described. 
With Beare, Greek Theories of Elementary Cognition, p. 225, n. 2, I 
take <dvov to mean the organ, not the object. 

434 b DE ANIMA 

this, that all bodies are capable of being affected by smells 
15 and sounds, but that some on being acted upon, having no 
boundaries of their own, disintegrate, as in the instance of air, 
which does become odorous, showing that some effect is 
produced on it by what is odorous? But smelling is more 
than such an affection by what is odorous what more ? Is 
not the answer that, while the air owing to the momentary 
duration of the action upon it of what is odorous does 
itself become perceptible to the sense of smell, smelling is 
an observing of the result produced ? l 

1 Here Aristotle (vainly) endeavours to bridge the gap between the 
two senses of perceiving , (a) the physical affection of the sense-organ 
by the sensigenous object, and (b) the psychical activity or reaction 
which consists in becoming or being aware of its sensible quality. 


i THAT there is no sixth sense in addition to the five enu 
meratedsight, hearing, smell, taste, touch may be estab 
lished by the following considerations : 

If we have actually sensation of everything of which touch 
can give us sensation (for all the qualities of the tangible qua 3 5 
tangible are perceived by us through touch) ; and if absence 
of a sense necessarily involves absence of a sense-organ ; and 
if (i) all objects that we perceive by immediate contact with 
them are perceptible by touch, which sense we actually 
possess, and (2) all objects that we perceive through media, 
i. e. without immediate contact, are perceptible by or through 3 
the simple elements, e.g. air and water (and this is so arranged 
that (a) if more than one kind of sensible object is perceivable 
through a single medium, the possessor of a sense-organ 
homogeneous with that medium has the power of perceiving 
both kinds of objects ; for example, if the sense-organ is 
made of air, and air is a medium both for sound and for 
colour; and that (b] if more than one medium can transmit 
the same kind of sensible objects, as e.g. water as well as 425* 
air can transmit colour, both being transparent, then the 
possessor of either alone will be able to perceive the kind 
of objects transmissible through both) ; and if of the simple 
elements two only, air and water, go to form .sense-organs 
(for the pupil is made of water, the organ of hearing is made 
of air, and the organ of smell of one or other of these two, 
while fire is found either in none or in all warmth being 5 
an essential condition of all sensibility and earth either in 
none or, if anywhere, specially mingled with the components 
of the organ of touch ; wherefore it would remain that there 
can be no sense-organ formed of anything except water 
and air) ; and if these sense-organs are actually found in 
certain animals; then all the possible senses are possessed 
by those animals that are not imperfect or mutilated (for 10 
even the mole is observed to have eyes beneath its skin) ; 
so that, if there is no fifth element and no property other 
than those which belong to the four elements of our world, 
no sense can be wanting to such animals. 

425 a DE ANIMA 

Further, there cannot be a special sense-organ for the 

15 common sensibles either, i. e. the objects which we perceive 
incidentally through this or that special sense, e.g. move 
ment, rest, figure, magnitude, number, unity ; for all these 
we perceive by movement, e. g. magnitude by movement, 
and therefore also figure (for figure is a species of magnitude), 
what is at rest by the absence of movement: number is 
perceived by the negation of continuity, and by the special 
sensibles ; for each sense perceives one class of sensible 

30 objects. So that it is clearly impossible that there should 
be a special sense for any one of the common sensibles, eg. 
movement ; for, if that were so, our perception of it would 
be exactly parallel to our present perception of what is 
sweet by vision. That is so because we have a sense for 
each of the two qualities, in virtue of which when they 
happen to meet in one sensible object we are aware of both 
contemporaneously. If it were not like this our perception 

35 of the common qualities would always be incidental, i.e. as 
is the perception of C Icon s son, where we perceive him not 
as Cleon s son but as white, and the white thing which we 
really perceive happens to be Cleon s son. 

But in the case of the common sensibles there is already 
in us a general sensibility which enables us to perceive them 
directly; there is therefore no special sense required for 
their perception : if there were, our perception of them would 
have been exactly like what has been above 1 described. 

30 The senses perceive each other s special objects incident 
ally ; not because the percipient sense is this or that special 
sense, but because all form a unity : this incidental perception 
takes place whenever sense is directed at one and the same 
moment to two disparate qualities in one and the same ob- 
425 b ject, e.g. to the bitterness and the yellowness of bile; the 
assertion of the identity of both cannot be the act of either 
of the senses; hence the illusion of sense, e.g. the belief that 
if a thing is yellow it is bile. 

It might be asked why we have more senses than one. 

5 Is it to prevent a failure to apprehend the common sensibles, 
e.g. movement, magnitude, and number, which go along with 

1 11. 24-7- 

BOOK III. I 4 25 b 

the special sensibles? Had we no sense but sight, and that 
sense l no object but white, they would have tended to escape 
our notice and everything would have merged for us into an 
indistinguishable identity because of the concomitance of 
colour and magnitude. As it is, the fact that the common sen 
sibles are given in the objects of more than one sense reveals 
their distinction from each and all of the special sensibles. *o 

2 Since it is through sense that we are aware that we are 
seeing or hearing, it must be either by sight that we are 
aware of seeing, or by some sense other than sight. But the 
sense that gives us this new sensation must perceive both 
sight and its object, viz. colour: so that either (i) there 
will be two senses both percipient of the same sensible 
object, or (2) the sense must be percipient of itself. Further, 15 
even if the sense which perceives sight were different from 
sight, we must either fall into an infinite regress, or we must 
somewhere assume a sense which is aware of itself. If so, 
we ought to do this in the first case. 

This presents a difficulty: if to perceive by sight is just 
to see, and what is seen is colour (or the coloured), then if 
we are to sec that which sees, that which sees originally 
must be coloured. It is clear therefore that to perceive by *o 
sight has more than one meaning ; for even when we are 
not seeing, it is by sight that we discriminate darkness from 
light, though not in the same way as we distinguish one 
colour from another. Further, in a sense even that which sees 
is coloured ; for in each case the sense-organ is capable of 
receiving the sensible object without its matter. That is 
why even when the sensible objects are gone the sensings 25 
and imaginings continue to exist in the sense-organs. 

The activity of the sensible object and that of the per 
cipient sense is one and the same activity, and yet the 
distinction between their being remains. Take as illustra 
tion actual sound and actual hearing : a man may have 
hearing and yet not be hearing, and that which has a sound 
is not always sounding. But when that which can hear is 
actively hearing and that which can sound is sounding, then 30 
1 Reading in 1. 7 aur/y, with Jackson. 

4*5 b DE ANIMA 

the actual hearing and the actual sound are merged in one 

426"* (these one might call respectively hearkening and sounding). 

If it is true that the movement, bolh the acting and the 

being acted upon, is to be found in that which is acted upon, 1 

both the sound and the hearing so far as it is actual must 

be found in that which has the faculty of hearing ; for it is 

in the passive factor that the actuality of the active or motive 

5 factor is realized ; that is why that which causes movement 
may be at rest. Now the actuality of that which can sound 
is just sound or sounding, and the actuality of that which can 
hear is hearing or hearkening; sound and hearing are 
both ambiguous. The same account applies to the other 
senses and their objects. For as the-acting-and-being-acted- 

10 upon is to be found in the passive, not in the active factor, so 
also the actuality of the sensible object and that of the sen 
sitive subject are both realized in the latter. But while in 
some cases each aspect of the total actuality has a distinct 
name, e.g. sounding and hearkening, in some one or other is 
nameless, e.g. the actuality of sight is called seeirg, but the 
actuality of colour has no name: the actuality of the 
faculty of taste is called tasting, but the actuality of flavour 

15 has no name. Since the actualities of the sensible object and 
of the sensitive faculty are one actuality in spite of the 
difference between their modes of, actual hearing 
and actual sounding appear and disappear from existence 
at one and the same moment, and so actual savour and 
actual tasting, &c., while as potentialities one of them may 

20 exist without the other. The earlier students of nature 
were mistaken in their view that without sight there was 
no white or black, without taste no savour. This statement 
of theirs is partly true, partly false: sense and the sensible 
object are ambiguous terms, i.e. may denote either poten- 

35 tialities or actualities : the statement is true of the latter, false 
of the former. This ambiguity they wholly failed to notice. 

If voice always implies a concord, 2 and if the voice and 
the hearing of it are in one sense one and the same, 3 and if 

1 Cf. Phys. iii. 3. 

2 Read in 1. 27 17 $<*>vr) o-i /K/xowa, with Sophonias and Priscianus. 

3 Omitting K<U . . . ouro in 1. 28, with Torstrik. 

BOOK III. 2 426* 

concord always implies a ratio, hearing as well as what 
is heard must be a ratio. That is why the excess of either 30 
the sharp or the flat destroys the hearing. (So also in the 
case of savours excess destroys the sense of taste, and in the 
case of colours excessive brightness or darkness destroys the 
sight, and in the case of smell excess of strength whether in 
the direction of sweetness or bitterness is destructive.) This 
shows that the sense is a ratio. 

That is also why the objects of sense are (i) pleasant 
when the sensible extremes such as acid or sweet or 
salt being pure and unmixed are brought into the proper 
ratio ; 1 then they are pleasant : and in general what is 5 
blended is more pleasant 2 than the sharp or the flat alone ; 
or, to touch, that which is capable of being either warmed 
or chilled : the sense and the ratio are identical : while (2) in 
excess the sensible extremes are painful or destructive. 

Each sense then is relative to its particular group of 
sensible qualities: it is found in a sense-organ as such 3 
and discriminates the differences which exist within that 
group ; e.g. sight discriminates white and black, taste sweet 10 
and bitter, and so in all cases. Since we also discriminate 
white from sweet, and indeed each sensible quality from 
every other, with what do we perceive that they are differ 
ent? It must be by sense; for what is before us is sensible 
objects. (Hence it is also obvious that the flesh cannot be 15 
the ultimate sense-organ : if it were, the discriminating power 
could not do its work without immediate contact with the 

Therefore (i) discrimination between white and sweet 
cannot be effected by two agencies which remain separate ; 
both the qualities discriminated must be present to some 
thing that is one and single. On any other supposition 
even if I perceived sweet and you perceived white, the 
difference between them would be apparent. What says 20 
that two things are different must be one ; for sweet is 

1 i.e. that which is involved in the structure of the sense-organ. 

2 Omit ovpipwia in 1. 6. 

8 The qualification appears to mean that the sense-organ may in other 
respects have other qualities. Thus the tongue can touch as well as 

645-19 F 

4a6 b DE ANIMA 

different from white. Therefore what asserts this difference 
must be self-identical, and as what asserts, so also what 
thinks or perceives. That it is not possible by means of 
two agencies which remain separate to discriminate two 
objects which are separate, is therefore obvious ; and that 
(2) it is not possible to do this in separate moments of time 
may be seen if we look at it as follows. For as what asserts 
the difference between the good and the bad is one and the 
3 same, so also the time at which it asserts the one to be 
different and the other to be different is not accidental 
to the assertion (as it is for instance when I now assert 
a difference but do not assert that there is now a 
difference) ; it asserts thus both now and that the objects 
are different now ; the objects therefore must be present 
at one and the same moment. Both the discriminating 
power and the time of its exercise must be one and 

But, it may be objected, it is impossible that what is 
3 self-identical should be moved at one and the same time 
with contrary movements in so far as it is undivided, and 
in an undivided moment of time. For if what is sweet be 
the quality perceived, it moves the sense or thought in this 
4 2 7 & determinate way, while what is bitter moves it in a contrary 
way, and what is white in a different way. Is it the 
case then that what discriminates, though both numerically 
one and indivisible, is at the same time divided in its being? 
In one sense, it is what is divided that perceives tv\o separate 
objects at once, but in another sense it does so qua undivided; 
for it is divisible in its being, but spatially and numerically 

5 But is not this impossible? For while it is true that 
what is self-identical and undivided may be both contraries 
at once potentially, it cannot be self-identical in its being 
it must lose its unity by being put into activity. It is not 
possible to be at once white and black, and therefore it must 
also be impossible for a thing to be affected at one and the 
same moment by the forms of both, assuming it to be the 
case that sensation and thinking are properly so described. 1 

1 i.e. as the being affected by the forms of sensible qualities. 


The answer is that just as what is called a point is, as 10 
being at once one and two, 1 properly said to be divisible, so 
here, that which discriminates is qua undivided one, and 
active in a single moment of time, while so far forth as it is 
divisible it twice over uses the same 2 dot at one and the 
same time. So far forth then as it takes the limit as two, 
it discriminates two separate objects with what in a sense is 
divided : while so far as it takes it as one, it does so with 
what is one 3 and occupies in its activity a single moment 
of time. 

About the principle in virtue of which we say that animals 
are percipient, let this discussion suffice. 15 

3 There are two distinctive peculiarities by reference to 
which we characterize the soul (i) local movement and 
(2) thinking, discriminating, and perceiving. Thinking both 
speculative and practical is regarded as akin to a form of 
perceiving ; for in the one as well as the other the soul ao 
discriminates and is cognizant of something which is. In 
deed the ancients go so far as to identify thinking and 
perceiving; e.g. Empedocles says 4 For tis in respect of 
what is present that man s wit is increased , and again 5 
* Whence it befalls them from time to time to think diverse 
thoughts , and Homer s phrase 6 For suchlike is man s mind* 2-5 
means the same. They all look upon thinking as a bodily 
process like perceiving, and hold that like is known as well 
as perceived by like, as I explained at the beginning of our 
discussion. 7 Yet they ought at the same time to have 
accounted for error also ; for it is more intimately connected 427 b 
with animal existence and the soul continues longer in the 
state of error than in that of truth. They cannot escape 
the dilemma: either (i) whatever seems is true (and there 
are some who accept this) or (2) error is contact with the 
unlike ; for that is the opposite of the knowing of like 
by like. 

But it is a received principle that error as well as know- 5 
ledge in respect to contraries is one and the same. 

1 Read in 1. 10 17 /i/a *ai dvo (?) pin K<U duo cod. L). 

2 Read in 1. 12 Simperoi/ un-up^et, dls TO) nvrw, with most MSS. and 
Alexander. s Read in 1. 14 ci/i, e vi. 

4 Fr. 106. 5 Fr. 108. 6 Od. xviii. 136. 7 4O4 b 8-18. 

F 2 

427 b DE ANIMA 

That perceiving and practical thinking are not identical 
is therefore obvious ; for the former is universal in the 
animal world, the latter is found in only a small division of 
it. Further, speculative thinking is also distinct from per 
ceiving I mean that in which we find Tightness and wrong- 

10 ness rightness in prudence, knowledge, true opinion, wrong- 
ness in their opposites ; for perception of the special objects 
of sense is always free from error, and is found in all animals, 
while it is possible to think falsely as well as truly, and 
thought is found only where there is discourse of reason 
as well as sensibility. For imagination is different from 

15 either perceiving or discursive thinking, though it is not 
found without sensation, or judgement without it. That 
this activity is not the same kind of thinking as judge 
ment is obvious. For imagining lies within our own 
power whenever we wish (e. g. we can call up a picture, as in 
the practice of mnemonics by the use of mental images), 

20 but in forming opinions we are not free : we cannot escape 
the alternative of falsehood or truth. Further, when we 
think something to be fearful or threatening, emotion is 
immediately produced, and so too with what is encouraging ; 
but when we merely imagine we remain as unaffected as 
persons who are looking at a painting of some dreadful or 
encouraging scene. Again within the field of judgement 

35 itself we find varieties knowledge, opinion, prudence, and 
their opposites ; of the differences between these I must 
speak elsewhere. 1 

Thinking is different from perceiving and is held to be in 
part imagination, in part judgement : we must therefore first 
mark off the sphere of imagination and then speak of judge- 
428* ment. If then imagination is that in virtue of which an 
image arises for us, excluding metaphorical uses of the 
term, is it 2 a single faculty or disposition relative to 
images, in virtue of which we discriminate and are either 
in error or not ? The faculties in virtue of which we do 
this are sense, opinion, science, intelligence. 

5 That imagination is not sense is clear from the following 

1 The reference is perhaps to E. N. i I39 b 15 ff. 

2 Read in 11. 3-4 (apa) pa . . 

BOOK III. 3 428* 

considerations : Sense is either a faculty or an activity, e.g. 
sight or seeing : imagination takes place in the absence of 
both, as e.g. in dreams. (2) Again, sense is always present, 
imagination not. If actual imagination and actual sensation 
were the same, imagination would be found in all the brutes: 
this is held not to be the case ; e. g. it is not found in ants 10 
or bees or grubs. (3) Again, sensations are always true, 
imaginations are for the most part false. (4) Once more, 
even in ordinary speech, we do not, when sense functions 
precisely with regard to its object, say that we imagine it 
to be a man, but rather when there is some failure of accu 
racy in its exercise. And (5), as we were saying before, 1 15 
visions appear to us even when our eyes are shut. 
Neither is imagination any of the things that are never 
in error: e.g. knowledge or intelligence; for imagination 
may be false. 

It remains therefore to see if it is opinion, for opinion 
may be either true or false. 

But opinion involves belief (for without belief in what 20 
we opine we cannot have an opinion), and in the brutes 
though we often find imagination we never find belief. 
Further, every opinion is accompanied by belief, belief by 
conviction, and conviction by discourse of reason : while 
there are some of the brutes in which we find imagination, 
without discourse of reason. 2 It is clear then that imagi 
nation cannot, again, be (i) opinion///^ sensation, or (2) 25 
opinion mediated by sensation, or (3) a blend of opinion 
and sensation ; 3 this is impossible both for these reasons 
and because 4 the content of the supposed opinion cannot 
be different from that of the sensation (I mean that imagi 
nation must be the blending of the perception of white with 
the opinion that it is white : it could scarcely be a blend of 
the opinion that it is good with the perception that it 30 
is white): to imagine is therefore (on this view) identical 428 b 
with the thinking of exactly the same as what one in the 
strictest sense perceives. But what we imagine is sometimes 

1 11. 7-8. 2 Retaining rt . . . oil in 11. 22-4. 

3 For these three views cf. PI. Tim. 52 A, Soph. 264 A, B, Phil. 39 B. 

4 Omit d^Xov in 1. 27, with Shorey. 


false though our contemporaneous judgement about it is true; 
e.g. we imagine the sun to be a foot in diameter though we 
are convinced that it is larger than the inhabited part of the 
earth, and the following dilemma presents itself. Either (a) 
while the fact has not changed and the observer has neither 

5 forgotten nor lost belief in the true opinion which he had 
that opinion has disappeared, or (b) if he retains it then his 
opinion is at once true and false. A true opinion, however, 
becomes false only when the fact alters without being 

Imagination is therefore neither any one of the states 
enumerated, nor compounded out of them. 

10 But since when one thing has been set in motion another 
thing may be moved by it, and imagination is held to be a 
movement and to be impossible without sensation, i. e. to 
occur in beings that are percipient and to have for its content 
what can be perceived, and since movement may be produced 
by actual sensation and that movement is necessarily similar 
in character to the sensation itself, this movement must be (i) 

15 necessarily (a) incapable of existing apart from sensation, 
(b) incapable of existing except when we perceive, (2) such 
that in virtue of its possession that in which it is found may 
present various phenomena both active and passive, and 
(3) such that it may be either true or false. 

The reason of the last characteristic is as follows. Percep 
tion (i) of the special objects of sense is never in error or 
admits the least possible amount of falsehood. (2) That of 
the concomitance of the objects concomitantwith the sensible 

30 qualities l comes next : in this case certainly we may be 
deceived ; for while the perception that there is white before 
us cannot be false, the perception that what is white is this 
or that may be false. (3) Third comes the perception of 
the universal attributes which accompany the concomitant 
objects to which the special sensibles attach (I mean e. g. 
of movement and magnitude) ; it is in respect of these that 
the greatest amount of sense-illusion is possible. 

25 The motion which is due to the activity of sense in these 
three modes of its exercise will differ from the activity of 
1 Transfer a ... aiVfyroiy from 1. 24 to 1. 20 after raura, with Bywater. 

BOOK III. 3 428 b 

sense; 1 (i) the first kind of derived motion is free from 
error while the sensation is present; (2) and (3) the others 
may be erroneous whether it is present or absent, especially 
when the object of perception is far off. If then imagination 3 
presents no other features than those enumerated and is 2 
what we have described, then imagination must be a 429* 
movement resulting from an actual exercise of a power of 

As sight is the most highly developed sense, the name 
<f>avTacria (imagination) has been formed from 0ao? (light) 
because it is not possible to see without light. 

And because imaginations remain in the organs of sense 
and resemble sensations, animals in their actions are largely 5 
guided by them, some (i. e. the brutes) because of the non- 
existence in them of mind, others (i.e. men) because 
of the temporary eclipse in them of mind by feeling or 
disease or sleep. 

About imagination, what it is and why it exists, let so 
much suffice. 

4 Turning now to the part of the soul with which the soul 10 
knows and thinks (whether this is separable from the others 
in definition only, or spatially as well) we have to inquire 
(i) what differentiates this part, and (2) how thinking can 
take place. 

If thinking is like perceiving, it must be either a process 
in which the soul is acted upon by what is capable of 
being thought, or a process different from but analogous to 
that. The thinking part of the soul must therefore be, while 5 
impassible, capable of receiving the form of an object ; that is 
must be potentially identical in character with its object 
without being the object. Mind must be related to what 
is thinkable, as sense is to what is sensible. 

Therefore, since everything is a possible object of thought, 
mind in order, as Anaxagoras says, 3 to dominate, that is, to 
know, must be pure from alladmixture ; for the co-presence of ao 
what is alien to its nature is a hindrance and a block : it follows 

1 Retaining rfjs aicrdfjvcvs in 1. 26. 

2 Read eVri in 1. i, with Bekker. 8 Fr. 12. 

429 a DE ANIMA 

that it too, like the sensitive part, can have no nature of its 
own, other than that of having a certain capacity. Thus 
that in the soul which is called mind (by mind I mean 
that whereby the soul thinks and judges) is, before it 

thinks, not actually any real thing. For this reason it 
cannot reasonably be regarded as blended with the body : 

25 if so, it would acquire some quality, e.g. warmth or cold, or 
even have an organ like the sensitive faculty : as it is, it 
has none. It was a good idea to call the soul the place 
of forms , 1 though (i) this description holds only of the 
intellective soul, and (2) even this is the forms only 

potentially, not actually. 

Observation of the sense-organs and their employment 

30 reveals a distinction between the impassibility of the sen 
sitive and that of the intellective faculty. After strong 
stimulation of a sense we are less able to exercise it than 
before, as e. g. in the case of a loud sound we cannot hear 
easily immediately after, or in the case of a bright colour 
or a powerful odour we cannot see or smell, but in the case 
of mind thought about an object that is highly intelligible 
renders it more and not less able afterwards to think 
objects that are less intelligible : the reason is that while 
the faculty of sensation is dependent upon the body, mind^ 
is separable from it. 

5 Once the mind has become each set of its possible 
objects, as a man of science has, when this phrase is used of 
one who is actually a man of science (this happens when he is 
now able to exercise the power on his own initiative), 2 its 
condition is still one of potentiality, but in a different sense 
from the potentiality which preceded the acquisition of know 
ledge by learning or discovery : the mind too is then able to 
think itself. 

10 Since we can distinguish between a spatial magnitude 
and what it is to be such, and between water and what it is to 
be water, and so in many other cases (though not in all ; 
for in certain cases the thing and its form are identical), 

1 The idea is Platonic, but the actual expression is not found in the 
extant works of Plato. 
8 Cf. i a 2i- b 2. 

BOOK III. 4 429 b 

flesh and what it is to be flesh are discriminated either by 
different faculties, 1 or by the same faculty in two different 
states : for flesh necessarily involves matter and is like what 
is snub-nosed, a this in a this? Now it is by means of 
the sensitive faculty that we discriminate the hot and the 
cold, i. e. the factors which combined in a certain ratio 15 
constitute flesh : the essential character of flesh is appre 
hended by something different either wholly separate from 
the sensitive faculty or related to it as a bent line to the 
same line when it has been straightened out. 

Again in the case of abstract objects what is straight is 
analogous to what is snub-nosed ; for it necessarily implies a 
continuum as its matter : its constitutive essence is different, 
if we may distinguish between straightness and what 
is straight : let us take it to be two-ness. It must be 20 
apprehended, therefore, by a different power or by the same 
power in a different state. To sum up, in so far as the 
realities it knows are capable of being separated from their 
matter, so it is also with the powers of mind. 

The problem might be suggested : if thinking is a passive 
affection, then if mind is simple and impassible and has 
nothing in common with anything else, as Anaxagoras says, 3 
how can it come to think at all? For interaction between 25 
two factors is held to require a precedent community of 
nature between the factors. Again it might be asked, is 
mind a possible object of thought to itself? For if mind is 
thinkable per se and what is thinkable is in kind one and 
the same, then either (a) mind will belong to everything, or 
(b) mind will contain some element common to it with all 
other realities which makes them all thinkable. 

(i) Have not we already disposed of the difficulty about 
interaction involving a common element, when we said 4 30 
that mind is in a sense potentially whatever is thinkable, 
though actually it is nothing until it has thought ? What 
it thinks must be in it just as characters may be said to be 430* 
on a writing-tablet on which as yet nothing actually 
stands written : this is exactly what happens with mind. 

1 Read in 1. 13 adpKa 77 aXXw, with most MSS. 

2 i.e. a particular form in a particular matter. 5 

particular matter. s Fr. 12. 4 a 15-24. 


(2) Mind is itself thinkable in exactly the same way as 
its objects are. For (a) in the case of objects which involve 
no matter, what thinks and what is thought are identical ; 
for speculative knowledge and its object are identical. 
5 (Why mind is not always thinking we must consider later) 1 
(b) In the case of those which contain matter each of the 
objects of thought is only potentially present. It follows 
that while they will not have mind in them (for mind is a 
potentiality of them only in so far as they are capable of 
being disengaged from matter) mind may yet be thinkable. 

10 Since in every class of things, as in nature as a whole, we 5 

find two factors involved, (i) a matter which is poten- 

1 tially all the particulars included in the class, (a) a cause 

which is productive in the sense that it makes them all 

(the latter standing to the former, as e.g. an art to its 

material), these distinct elements must likewise be found 

/within the soul. 

And in fact mind as we have described it <-i is what it is by 

15 virtue of becoming all things, while there is another which 
is what it is by virtue of making all things : this is a sort 
of positive state like light ; for in a sense light makes 
potential colours into actual colours. 

Mind in this sense of it is separable, impassible, unmixed, 
since it is in its essential nature activity (for always the 
active is superior to the passive factor, the originating force 

t to the matter which it forms). 

ao Actual knowledge is identical with its object: in the indivi 
dual, potential knowledge is in time prior to actual know 
ledge, but in the universe as a whole it is not prior even in 
time. 3 Mind is not at one time knowing and at another not 
When mind is set free from its present conditions it appears 
as just what it is and nothing more : this alone is immortal 
and eternal (we do not, however, remember its former 
activity because, while mind in^ this sense is impassible, 

3 5 mind as passive is destructible), 4 and without it nothing 

1 Ch 5. 2 In ch. 4. 

3 Reading in 1. 21 oi fie \povu>, with most MSS. and Themistius. 

4 ov . . . (jiOupTos in 11. 23-5 is probably parenthetical. 

BOOK III. 6 430 a 

6 The thinking then of the simple objects of thought is 
found in those cases where falsehood is impossible : 
where the alternative of true or false applies, there we 
always find a putting together of objects of thought in a 
quasi-unity. As Empedocles said that where heads of 
many a creature sprouted without necks 1 they afterwards by 
Love s power were combined, so here too objects of thought 30 
which were given separate are combined, e.g. incommen 
surate and diagonal : if the combination be of objects 
past or future the combination of thought includes in its 
content the date. For falsehood always involves a syn- 43O b 
thesis ; for even if you assert that what is white is not white 
you have included not-white in a synthesis. It is possible 
also to call all these cases division as well as combination. 
However that may be, there is not only the true or false 
assertion that Cleon is white but also the true or false asser 
tion that he was or will be white. In each and every case that 5 
which unifies is mind. 

Since the word simple has two senses, i. e. may mean 
either (a] not capable of being divided or (b) not actually 
divided \ there is nothing to prevent mind from knowing what 
is undivided, e.g. when it apprehends a length (which is 
actually undivided) and that in an undivided time ; for 
the time is divided or undivided in the same manner as the 
line. It is not possible, then, to tell what part of the line it 10 
was apprehending 2 in each half of the time: the object 
has no actual parts until it has been divided : if in thought 
you think each half separately, then by the same act you 
divide the time also, the half-lines becoming as it were new 
wholes of length. But if you think it as a whole consisting 
of these two possible parts, then also you think it in a 
time which corresponds to both parts together. (But what 
is not quantitatively but qualitatively simple is thought in 15 
a simple time and by a simple act of the soul.) 3 

But that which 4 mind thinks and the time in which it 

1 Fr. 57. "Reading eVo ei in 1. 10, with cod. L. 

3 11. 14-15 TO ... tyvxrjs, dealing not, like the rest of 11 6-20, with the 

quantitatively divisible though undivided but with the qualitatively 
simple, should either be treated as a parenthesis, or placed, as By water 
places it, after /^ei in 1. 20. 

4 Read in 1. 16 6 i>oel, with Vicomercatus and Bywater. 

430 b DE ANIMA 

thinks are in this case divisible only incidentally and not as 
such. For in them too there is something indivisible (though, , 
it may be, not isolable) which gives unity to the time and the 
whole of length ; and this is found equally in every con 
tinuum whether temporal or spatial. 

20 Points and similar instances of things that divide, them 
selves being indivisible, are realized in consciousness in the 
same manner as privations. 

A similar account may be given of all other cases, e. g. 
how evil or black is cognized ; they are cognized, in a sense, 
by means of their contraries. That which cognizes must 
have an element of potentiality in its being, and one of the 
contraries must be in it. 1 But if there is anything that has 

25 no contrary, then it knows itself and is actually and possesses 
independent existence. 

Assertion is the saying of somethingconcerning something, 
e. g. affirmation, and is in every case either true or false : 
this is not always the case with mind : the thinking of the 
definition in the sense of the constitutive essence is never in 
error nor is it the assertion of something concerning some 
thing, but, just as while the seeing of the special object of 
sight can never be in error, the belief that the white object 

30 seen is a man may be mistaken, so too in the case of objects 
which are without matter. 

43 1 * Actual knowledge is identical with its object : potential 7 
knowledge in the individual is in time prior to actual know 
ledge but in the universe it has no priority even in time ; for all 
things that come into being arise from what actually is. In 
the case of sense clearly the sensitive faculty already was 
5 potentially what the object makes it to be actually ; the 
faculty is not affected or altered. This must therefore be a 
different kind from movement ; for movement is, as we saw, 2 
an activity of what is imperfect, activity in the unqualified 
sense, i.e. that of what has been perfected, is different from 

1 i.e. it must be characterized actually by one and potentially by the 
other of the contraries. Omit TO>I/ mnW in 1. 25 and read T>V 
(so cod. S in 1. 25) ev avru> after cv clvcn in 1. 24. 

2 Cf. 4i; b 2-i6. 

BOOK III. 7 43i 

To perceive then is like bare asserting or knowing ; but 
when the object is pleasant or painful, the soul makes a 
quasi-affirmation or negation, and pursues or avoids the 
object. To feel pleasure or pain is to act with the sensitive 10 
mean towards what is good or bad as such. Both avoidance 
and appetite when actual are identical with this: the faculty 
of appetite and avoidance are not different, either from one 
another or from the faculty of sense-perception ; but their 
being is different. 

To the thinking soul images serve as if they were con 
tents of perception (and when it asserts or denies them to 15 
be good or bad it avoids or pursues them). That is why the 
soul never thinks without an image. The process is like that 
in which the air modifies the pupil in this or that way and 
the pupil transmits the modification to some third thing 
(and similarly in hearing), while the ultimate point of 
arrival is one, a single mean, with different manners of 

With what part of itself the soul discriminates sweet 20 
from hot 1 I have explained before 2 and must now describe 
again as follows : That with which it does so is a sort of 
unity, but in the way just mentioned, 3 i. e. as a connecting 
term. And the two faculties it connects, 4 being one by analogy 
and numerically, 5 are each 6 to each as the qualities discerned 
are to one another (for what difference does it make whether 
we raise the problem of discrimination between disparates or 
between contraries, e. g. white and black ?). Let then C be 25 
to D as A is to B : 7 it follows alter nando that C : A \\D\B. 
If then C and D belong to one subject, the case will be the 
same with them as with A and B ; A and B form a single 

1 i.e. the sweetness and the heat in a sweet-hot object. 

2 426** I2~427 a 14. 3 i.e. as one thing with two aspects ; cf. 1. 19. 
4 i. e. the faculty by which we discern sweet and that by which we 

discern hot. 

6 i.e. (i) by standing in an analogical relation to their objects (cf. 11. 
25-7) and (2) by belonging to the one eo-^aroi/ maBrjr^piov (cf. 11. 27-9). 

8 Reading in 1. 23 e\d (e Karepoj>). 

7 i.e. let the faculty that discerns sweet be to that which discerns 
hot as sweet is to hot. Omit TO \fvKov and TO / X<u> in 11. 25-6 ; the 
point seems to be that the power of discerning sweet and the power of 
discerning hot belongs to the same subject (the eo-^aTOf atV^T^ptoi/) as 
sweetness and heat may belong to the same object. 

43i a DE ANIMA 

identity with different modes of being ; so too will the former 
43 1 pair. The same reasoning holds if A be sweet and B white. 
The faculty of thinking then thinks the forms in the 
images, and as in the former case l what is to be pursued 
or avoided is marked out for it, so where there is no 
sensation and it is engaged upon the images it is moved 
5 to pursuit or avoidance. E.g. perceiving by sense that the 
beacon is fire, it recognizes in virtue of the general faculty 
of sense that it signifies an enemy, because it sees it 
moving ; but sometimes by means of the images or thoughts 
which are within the soul, just as if it were seeing, it calculates 
and deliberates what is to come by reference to what is 
present ; and when it makes a pronouncement, as in the case of 
sensation it pronounces the object to be pleasant or painful, in 
this case it avoids or pursues; and so generally in cases of 

10 That too which involves no action, i.e. that which is 
true or false, is in the same province with what is good or 
bad : yet they differ in this, that the one set imply and the 
other do not a reference to a particular person. 

The so-called abstract objects the mind thinks just as, 
if one had thought of the snub-nosed not as snub-nosed but 
as hollow, one would have thought of an actuality without 

15 the flesh in which it is embodied: 2 it is thus that the mind when 
it is thinking the objects of Mathematics thinks as separate 
elements which do not exist separate. In every case the 
mind which is actively thinking is the objects which it 
thinks. Whether it is possible for it while not existing 
separate from spatial conditions to think anything that 
is separate, or not, we must consider later. 3 

30 Let us now summarize our results about soul, and repeat 8 
that the soul is in a way all existing things ; for existing 
things are either 4 sensible or thinkable, and knowledge is in 

1 i.e. that of sense-data. 

2 Reading in 11. 13-15 (after By water, in the main) d (TU) TO aipov, 
rj fjitv tn^ov ou [Kex^pKr/ifcun], rj 8e KOiAov [ TIS] evoti, ev^pyaav avtv 
rf)S aapKos iiv fio-i fv jy [TO AcoiAof]. 

3 This promise does not seem to h ive been fulfilled. 

4 Reading in 1. 21 can ndvra f) ya/j,with most MSb., Them., Phil., and 
the Vetus Iranslatio. 

BOOK III. 8 43i b 

a way what is knowable, and sensation is in a way what is 
sensible : in what way we must inquire. 

Knowledge and sensation are divided to correspond 
with the realities, potential knowledge and sensation 3 . 
answering to potentialities, actual knowledge and sensation 
to actualities. Within the soul the faculties of knowledge 
and sensation are potentially these objects, the one what 
is knowable, the other what is sensible. 1 They must be 
either the things themselves or their forms. The former 
alternative is of course impossible : it is not the stone which 
is present in the soul but its form. 

It follows that the soul is analogous to the hand ; for 432* 
as the hand is a tool of tools, 2 so the mind is the form of 
forms and sense the form of sensible things. 

Since according to common agreement there is nothing 
outside and separate in existence from sensible spatial 
magnitudes, the objects of thought are in the sensible 
forms, viz. both the abstract objects and all the states 5 
and affections of sensible things. Hence (i) no one can 
learn or understand anything in the absence of sense, and 
(2) when the mind is actively aware of anything it is 
necessarily aware of it along with an image; for images are 
like sensuous contents except in that they contain no 

Imagination is different from assertion and denial ; for 
what is true or false involves a synthesis of concepts. In I0 
what will the primary concepts differ from images ? Must 
we not say that neither these nor even our other concepts 
are images, though they necessarily involve them ? 

The soul of animals is characterized by two faculties, (a) Ig 
the faculty of discrimination which is the work of thought 
and sense, and (b) the faculty of originating local movement. 
Sense and mind we have now sufficiently examined. Let 
us next consider what it is in the soul which originates 
movement. Is it a single part of the soul separate either 

1 Reading in 1. 27 ravra with E a , Sophonias, and the Vetus Trans- 

2 i.e. a tool for using tools. 

43a a DE ANIMA 

20 spatially or in definition ? Or is it the soul as a whole ? If 
it is a part, is that part different from those usually distin 
guished or already meniioned by us, or is it one of them ? 
The problem at once presents itself, in what sense we are 
to speak of parts of the soul, or how many we should 
distinguish. For in a sense there is an infinity of parts : 

25 it is not enough to distinguish, with some thinkers, 1 the cal- 
culative, the passionate, and the desiderative, or with others 2 
the rational and the irrational; for if we take the dividing 
lines followed by these thinkers we shall find parts far more 
distinctly separated from one another than these, namely those 
we have just mentioned: (i) the nutritive, \\hichbelongsboth 

30 to plants and to all animals, and (2) the sensitive, which cannot 
easily be classed as either irrational or rational ; further (3) 
432 b the imaginative, which is. in its being, different from all, 
while it is very hard to say with which of the others it is 
the same or not the same, supposing we determine to posit 
separate parts in the soul ; and lastly (4) the appetitive, 
which would seem to be distinct both in definition and in 
power from all hitherto enumerated. 

5 It is absurd to break up the last-mentioned faculty : as 
these thinkers do, for wish is found in the calculative part 
and desire and passion in the irrational ; 3 and if the soul 
is tripartite appetite will be found in all three parts. 
Turning our attention to the present object of discussion, 
let us ask what that is which originates local movement of 
the animal. 

The movement of growth and decay, being found in all 

10 living things, must be attributed to the faculty of reproduc 
tion and nutrition, which is common to all : inspiration 
and expiration, sleep and waking, we must consider later: * 
these too present much difficulty : at present we must consider 
local movement, asking what it is that originates forward 
movement in the animal. 

15 That it is not the nutritive faculty is obvious ; for this 
kind of movement is always for an end and is accompanied 

1 PI. Rep. 435-41. 2 A popular view, cf. E.N. iiO2 n 26-8. 

8 All three being forms of appetite. 
4 Cf. DC Respiratione, De Soinno. 

BOOK III. 9 43 b 

either by imagination or by appetite ; for no animal moves 
except by compulsion unless it has an impulse towards or 
away from an object. Further, if it were the nutritive faculty, 
even plants would have been capable of originating such 
movement and would have possessed the organs necessary 
to carry it out. Similarly it cannot be the sensitive 
faculty either; for there are many animals which have 
sensibility but remain fast and immovable throughout their 
lives. *o 

If then Nature never makes anything without a purpose 
and never leaves out what is necessary (except in the case 
of mutilated or imperfect growths ; and that here we have 
neither mutilation nor imperfection may be argued from 
the facts that such animals (a) can reproduce their species 
and (b) rise to completeness of nature and decay to an end), 
it follows that, had they been capable of originating forward *5 
movement, they would have possessed the organs necessary 
for that purpose. Further, neither can the calculative faculty 
or what is called * mind be the cause of such movement ; 
for mind as speculative never thinks what is practicable, it 
never says anything about an object to be avoided or 
pursued, while this movement is always in something which 
is avoiding or pursuing an object. No, not even when it is 
aware of such an object does it at once enjoin pursuit or 3P 
avoidance of it; e.g. the mind often thinks of something 
terrifying or pleasant without enjoining the emotion of 
fear. It is the heart that is moved (or in the case of a 
pleasant object some other part). Further, even when the 433 a 
mind does command and thought bids us pursue or avoid 
something, sometimes no movement is produced ; we act in 
accordance with desire, as in the case of moral weakness. 
And, generally, we observe that the possessor of medical 
knowledge is not necessarily healing, which shows that some 
thing else is required to produce action in accordance with 
knowledge ; the knowledge alone is not the cause. Lastly, 5 
appetite too is incompetent to account fully for movement ; 
for those who successfully resist temptation have appetite 
and desire and yet follow mind and refuse to enact that 
for which they have appetite. 

433 a DE ANIMA 

These two at all events appear to be sources of mcvement : 10 
appetite and mind (if one may venture to regard imagina- 

10 tion as a kind of thinking ; for many men l follow their 
imaginations contrary to knowledge, and in all animals 
other than man there is no thinking or calculation but 
only imagination). 

Both of these then are capable of originating local move 
ment, mind and appetite: (i) mind, that is, which calcu 
lates means to an end, i.e. mind practical (it differs from 

15 mind speculative in the character of its end) ; while (2) 
appetite is in every form of it relative to an end : for that 
v^hich is the object of appetite is the stimulant of mind 
practical ; and that which is last in the process of thinking 
is the beginning of the action. It follows that there is a 
justification for regarding these two as the sources of move 
ment, i. e appetite and practical thought ; for the object 
of appetite starts a movement and as a result of that 
thought gives rise to movement, the object of appetite 

ao being to it a source of stimulation. So too when imagina 
tion originates movement, it necessarily involves appetite. 

That which moves therefore is a single faculty and the 
faculty of appetite ; for if there had been two sources of 
movement mind and appetite they would have produced 
movement in virtue of some common character. As it is, 
mind is never found producing movement without appetite 
(for wish is a form of appetite ; and when movement is 
produced according to calculation it is also according to 

35 wish), but appetite can originate movement contrary to 
calculation, for desire is a form of appetite. Now mind is 
always right, but appetite and imagination may be either 
right or wrong. That is why, though in any case it is the 
object of appetite which originates movement, this object 
may be either the real or the apparent good. To produce 
movement the object must be more than this : it mu>t be 
good that can be brought into being by action ; and only 

30 what can be otherwise than as it is can thus be brought into 
being. That then such a power in the soul as has been 
described, i.e. that called appetite, originates movement is 
1 Reading in 1. 10 n-oXXot, with Bywater. 

BOOK III. 10 433 b 

clear. Those who distinguish parts in the soul, if they 433 
distinguish and divide in accordance with differences of 
power, find themselves with a very large number of parts, 
a nutritive, a sensitive, an intellective, a deliberative, and now 
an appetitive part ; for these are more different from one 
another than the faculties of desire and passion. 

Since appetites run counter to one another, which happens 5 
when a principle of reason and a desire are contrary and 
is possible only in beings with a sense of time (for while 
mind bids us hold back because of what is future, desire is 
influenced by what is just at hand : a pleasant object which 
is just at hand presents itself as both pleasant and good, 
without condition in either case, because of want of foresight 
into what is farther away in time), it follows that while that 10 
which originates movement must be specifically one, viz. 
the faculty of appetite as such (or rather farthest back of all 
the object of that faculty ; for it is it that itself remaining 
unmoved originates the movement by being apprehended 
in thought or imagination), the things that originate 
movement are numerically many. 

All movement involves three factors, (i) that which 
originates the movement, (2) that by means of which it 
originates it, and (3) that which is moved. The expression 
* that which originates the movement is ambiguous : it 
may mean either (a) something which itself is unmoved or 
(b) that which at once moves and is moved. Here that 15 
which moves without itself being moved is the realizable 
good, that which at once moves and is moved is the faculty 
of appetite (for that which is influenced by appetite so far 
as it is actually so influenced is set in movement, and 
appetite in the sense of actual appetite is a kind of move 
ment), while that which is in motion is the animal. The 
instrument which appetite employs to produce movement 
is no longer psychical but bodily : hence the examination 20 
of it falls within the province of the functions common to 
body and soul. 1 To state the matter summarily at present, 
that which is the instrument in the production of movement 
is to be found where a beginning and an end coincide as 
1 Cf. De Motu An. 702* 2i-;o3 a 22. 

433 b DE ANIMA 

e. g. in a ball and socket joint ; for there the convex and 
the concave sides are respectively an end and a beginning 
(that is why while the one remains at rest, the other is 
moved) : they are separate in definition but not separable 

35 spatially. For everything is moved by pushing and pulling. 
Hence just as in the case of a wheel, so here there must be 
a point which remains at rest, and from that point the 
movement must originate. 

To sum up, then, and repeat what I have said, inasmuch 
as an animal is capable of appetite it is capable of self- 
movement ; it is not capable of appetite without possessing 
imagination ; and all imagination is either (i) calculative or 

30 (2) sensitive. In the latter all animals, and not only man, 

We must consider also in the case of imperfect animals, n 
sc. those which have no sense but touch, what it is that in 
434* them originates movement. Can they have imagination or 
not ? or desire ? Clearly they have feelings of pleasure and 
pain, and if they have these they must have desire. But 
how can they have imagination ? Must not we say that, as 
their movements are indefinite, they have imagination and 
desire, but indefinitely ? 

5 Sensitive imagination, as we have said, 1 is found in all 
animals, deliberative imagination only in those that are cal 
culative : for whether this or that shall be enacted is 
already a task requiring calculation ; and there must be a 
single standard to measure by, for that is pursued which is 
greater. It follows that what acts in this way must be able 
to make a unity out of several images. 

10 This is the reason why imagination is held not to involve 
opinion, in that it does not involve opinion based on 
inference, though opinion involves imagination. Hence 
appetite contains no deliberative element. Sometimes it 
overpowers wish and sets it in movement : at times wish acts 
thus upon appetite, like one sphere imparting its move 
ment to another, or appetite 2 acts thus upon appetite, 
i.e. in the condition of moral weakness (though by nature 
1 433 b 29. 2 Reading in 1. 14 qj? #petr, with Chandler. 

BOOK III. II 434 a 

the higher faculty is alzvays more authoritative and gives 
rise to movement). Thus three modes of movement are 
possible. 15 

The faculty of knowing is never moved but remains at 
rest. Since the one premiss or judgement is universal and 
the other deals with the particular (for the first tells us that 
such and such a kind of man should do such and such a kind of 
act, and the second that this is an act of the kind meant, and 
I a person of the type intended), it is the latter opinion that 
really originates movement, not the universal ; or rather it 20 
is both, but the one does so while it remains in a state 
more like rest, while the other partakes in movement. 

I2 The nutritive soul then must be possessed by everything 
that is alive, and every such thing is endowed with soul from 
its birth to its death. For what has been born must grow, 
reach maturity, and decay all of which are impossible 
without nutrition. Therefore the nutritive faculty must be 35 
found in everything that grows and decays. 

But sensation need not be found in all things that live. 
For it is impossible for touch to belong either (i) to those 
whose body is uncompounded or (2) to those which are 
incapable of taking in the forms without their matter. 

But animals must be endowed with sensation, since 30 
Nature does nothing in vain. For all things that exist by 
. Nature are means to an end, or will be concomitants of 
means to an end. Every body capable of forward move 
ment would, if unendowed with sensation, perish and fail 
to reach its end, which is the aim of Nature ; for how could it 434** 
obtain nutriment? Stationary living things, it is true, have 
as their nutriment that from which they have arisen ; but 
it is not possible that a body which is not stationary but 
produced by generation should have a soul and a discern 
ing mind without also having sensation. (Nor yet even if 
it were not produced by generation. 1 Why should it not 
have sensation ? Because it were better so either for the 5 
body or for the soul ? But clearly it would not be better 

Reading yfvvrjrov be . (dXXa p.fjv ot>e dyfvvrjTOv 8ia TI yap oi^ e^f i ; 
in 11. 4-7, with Platt. 

434 b DE AN IMA 

for either: the absence of sensation will not enable the 
one to think better or the other to exist better.) There 
fore no body which is not stationary has soul without sen 

But if a body has sensation, it must be either simple or 

10 compound. And simple it cannot be ; for then it could not 
have touch, which is indispensable. This is clear from what 
follows. An animal is a body with soul in it: every 
body is tangible, i. e. perceptible by touch ; hence neces 
sarily, if an animal is to survive, its body must have tac- 

15 tual sensation. All the other senses, e.g. smell, sight, 
hearing, apprehend through media ; but where there is 
immediate contact the animal, if it has no sensation, will 
be unable to avoid some things and take others, and so will 
find it impossible to survive. That is why taste also is a 
sort of touch ; it is relative to nutriment, which is just tan 
gible body; whereas sound, colour, and odour are innutri- 

30 tious, and further neither grow nor decay. Hence it is 
that taste also must be a sort of touch, because it is the 
sense for what is tangible and nutritious. 

Both these senses, then, are indispensable to the animal, 
and it is clear that without touch it is impossible for an 
animal to be. All the other senses subserve well-being 
and for that very reason belong not to any and every kind 

25 of animal, but only to some, e. g. those capable of forward 
movement must have them ; for, if they are to survive, they 
must perceive not only by immediate contact but also at a 
distance from the object. This will be possible if they can 
perceive through a medium, the medium being affected 
and moved by the perceptible object, and the animal by 

30 the medium. Just as that which produces local movement 
causes a change extending to a certain point, and that which 
gave an impulse causes another to produce a new impulse 
so that the movement traverses a medium the first mover 
impelling without being impelled, the last moved being im 
pelled without impelling, while the medium (or media, for 
435* there are many) is both so is it also in the case of altera 
tion, except that the agent produces it without the patient s 
changing its place. Thus if an object is dipped into wax, 

BOOK III. 12 435 a 

the movement goes on until submersion has taken place, 
and in stone it goes no distance at all, while in water the 
disturbance goes far beyond the object dipped : in air the 
disturbance is propagated farthest of all, the air acting and 
being acted upon, so long as it maintains an unbroken unity. 
That is why in the case of reflection it is better, instead of 5 
saying that the sight issues from the eye and is reflected, 
to say that the air, so long as it remains one, is affected by 
the shape and colour. On a smooth surface the air pos 
sesses unity ; hence it is that it in turn sets the sight in 
motion, just as if the impression on the wax were trans 
mitted as far as the wax extends. 10 

13 It is clear that the body of an animal cannot be simple, 
i. e. consist of one element such as fire or air. For with 
out touch it is impossible to have any other sense; for 
every body that has soul in it must, as we have said, 1 be 
capable of touch. All the other elements with the excep 
tion of earth can constitute organs of sense, but all of 15 
them bring about perception only through something else, 
viz. through the media. Touch takes place by direct con 
tact with its objects, whence also its name. All the other 
organs of sense, no doubt, perceive by contact, only the 
contact is mediate : touch alone perceives by immediate 
contact. Consequently no animal body can consist of 
these other elements. 

Nor can it consist solely of earth. For touch is as it ao 
were a mean between all tangible qualities, and its organ is 
capable of receiving not only all the specific qualities which 
characterize earth, but also the hot and the cold and all 
other tangible qualities whatsoever. That is why we have 
no sensation by means of bones, hair, &c.,. because they 35 
consist of earth. So too plants, because they consist of 435 b 
earth, have no sensation, Without touch there can be 
no other sense, and the organ of touch cannot consist of 
earth or of any other single element. 

It is evident, therefore, that the loss of this one sense 
alone must bring about the death of an animal. For as 5 

435 b DE ANIMA 

on the one hand nothing which is not an animal can have 
this sense, so on the other it is the only one which is indis 
pensably necessary to what is an animal. This explains, 
further, the following difference between the other senses 
and touch. In the case of all the others excess of intensity 
in the qualities which they apprehend, i.e. excess of inten 
sity in colour, sound, and smell, destroys not the animal 

10 but only the organs of the sense (except incidentally, as 
when the sound is accompanied by an impact or shock, or 
where through the objects of sight or of smell certain other 
things are set in motion, which destroy by contact) ; fla 
vour also destroys only in so far as it is at the same time 
tangible. 1 But excess of intensity in tangible qualities, e, g. 

15 heat, cold, or hardness, destroys the animal itself. As 
in the case of every sensible quality excess destroys the 
organ, so here what is tangible destroys touch, which is 
the essential mark of life ; for it has been shown that with 
out touch it is impossible for an animal to be. That is 
why excess in intensity of tangible qualities destroys not 
merely the organ, but the animal itself, because this is the 
only sense which it must have. 

All the other senses are necessary to animals, as we have 

20 said, 2 not for their being, but for their well-being, Such, 
e. g., is sight, which, since it lives in air or water, or gener 
ally in what is pellucid, it must have in order to see, and 
taste because of what is pleasant or painful to it, in order 
that it may perceive these qualities in its nutriment and so 
may desire to be set in motion, and hearing that it may 

35 have communication made to it, and a tongue that it may 
communicate with its fellows. 

1 Reading in 1. 13 anrov. 2 434 b 24. 


2 a_ 35 b = 

Abstract objects 29 b 18, 3i b 12. 

Abstraction 3 b i5. 

Achelous 2o b 12. 

Action 3i b 10, 33* 17. 

Activity, Actuality (eVpyeia) 17* 

1 6, 26 a 4, 7, 3o a i8, 3i a 6. Cf. 

Actual, Actually (cvcpyei a) 17*12, 
18, b i9, 24 a i,25 b 28, 29*24, b 6, 
30*17. Cf. Activity. 

Actuality, Actual, Actually (fW- 

28, I4 a 25, I5 b i4, 17*29, b 5, 29 a 

29, b 3O, 31*3, b 25. 
Age, old 8 b 22. 

Air 11*20, 19*32, b 34, 20* 8, 24 b 

15, 25*4, 35 a 4- 
Alcmaeon 5* 29. 
Alteration 6 a i2, 8 b ii, I7 b 6, 14, 

Anaxagoras 4 a 25, b I, 5 a 13, b 19, 

Anger 3* 26, 30. 

Animal 2 b 7, io b 19, n a i, b 20, 
I3 a 3, b 2, 33. M b 3, 16, 15*5, 

29, 25 a 10, 28 a lO, 32 b 2O, 23, 

33 b 30,34 a 6, 30, b 2, u, 24,35 a 

n, b i7. 

Ant I9 a i7, 28 a u. 
Aphrodite 6 b 19. 
Appetite, Appetitive (op*t?, opf<Ti- 

icdO 3 a 3o, I4 b i, 2, 31*12, 13, 

32 b 3, 33*18,20,27, 28, 31, b 5, 

12, 16. 

Axe I2 b i2. 

Belief 28* 20. 
Blood 5 b i4. 

Body I2 a 12, 18, b 6, 23, I3 a 2, I4 a 
18, I5 b 8, n, 16*28, i8 b 9, 12, 

17, 23*12, 24, b 27, 34*28, b 9, 
10, 12, 35 a u. 

Breath 2o b 20. 

Calculation, calculative 1 5* 8, 32* 
25, b 5> 26,33*12, 24, b 29, 34* 

Categories 2*25, 10*15. 


Colour i8 a 27, 31, 19*10. 
Concord 24 a 3i, 26*27, 29, b 6. 
Critias 5 b 6. 

Daedalus 6 b 18. 

Definition, definitive 7*25, 30, 13* 


Deliberative 34*7, 12. 
Democritus 3 b 3i, 4*27, 5*8, 6 b 

17, 9 a i2, 32, b 8, 19*15. 
Demonstration 2* 15, b 25, 7*26. 
Desire, desiderative (firiQufjua, em- 

GV^TIKOS) 7 a 5, I3 b 24, I4 b 2, 6, 

32*25, b 6, 33 a 25, b 4, 6, 34*3. 
Diagonal 30*31. 
Dialectician 3* 29. 
Diares i8 a 2i. 
Diogenes 5*21. 

Ear 20*9, I 3j 16. 

Earth 5 b 8, 6*28, 25 a 6, 35* I5, b l. 

Echo I9 b 25. 

Efflux i8 b 15, 22*15. 

Element 5 b 13, 9^4-11*7, 23*27, 
24 b 30-25* 13, 35 a n- b 3. 

Empedocles 4 b 1 1, 8 a 19, io a 3, 28, 
I5 b 28, i8 b 20, 27*22, 30*28. 

Error 27 b 4. 

Essence (ouaia) I5 b 13. Cf. Sub 

Eye I2 b 2o, 13*2. 

Eyelids 2i b 29. 

Figure I4 b 2i, 18*18, 25*18. 
Final cause I5 b 2, 10, 16, 20, i6 b 

24, 2o b i9, 3 2 b 2i,33*i4, 15, 34 b 

24, 35 b 20. 

Fire 4* I, 6 a 28, 16*9. 
Fishes 2O b 10, 21*4. 
Flavour I4 b 1 1, 13, 22* 6, b 10, 26 a 

1 S- 
Flesh 8* 1 5, 9 b 32, 23* 14, b 26, 26 b 

15, 29 b 12, 16. 

Food 16*22, 35, b 11, 12, 19, 23. 
Form 3 b 2, 12*8, 10, 14* 12, 16, 17, 

24* 1 8, 29* 15, 32* 2. Cf. Species. 

Generation 15*27, i6 b i5. 

Gills 24 b i3. 

Good 33 a 28, 29, b 9. 


Growth 6 a i3, ii a 3O, 13*27, I5 b 

29, 34 a 24. 
Grubs 28 a ii. 

Hand 32 a I. 

Harmonic numbers 6 b 29. 

Harmony 7 b 27-8* 28. 

Hearing I9 b 4~2i a 6, 2i b 4, 22 a 23, 

25 a 4, b 3o, 2 6 a 8, 29, 35 b 24. 
Heart 3 a 3i, 8 b 8, 32 b 3i. 
Hector 4 a 30. 
Heraciitus 5 a 25. 
Hippo 5 b 2. 
Homer 4 a 29, 27 a 25. 
Hunger I4 b 12. 

2, 4, 7, 

Idea (Platonic) 4 b 20. 

Image 2b a I, 3i a i6, 
8, 9 13, 34 a io. 

Imagination 3 a 8, I4 b i6, I5 a 10, 
11, 25 b 25, 27 b i4, 17, 27-29 a 9, 
32 a io, 31, 33 a io, 12, 27, b 29, 

34 a i,5- 

Immortal 3O a 23. 
Indivisible 3O b 2o. Cf. Simple, Un 


Insects li b 2O, I3 b 2o. 
Intention (7rpom /je<ny) 6 b 25. 
Irrational 32 a 26, 30. 

Joint 33 b 22. 
Judgement 27 b 25, 28. 

Kind io a i3, I2 a 6, I3 b 26, I7 a 27. 

Knowledge I2 a io, I4 a 9, 10, I7 a 
24, 26, b 23, 26, 27 b 6, 9, 28 a i6, 
29 b 6, 3o a 2o, 31* i, b 22, 23,27, 
34 a 16. 

Leucippus 4 a 5. 

Life 4 a 9, 5 b 27, I2 a i4, I3 a l9> 22, 

b i, I 4 a 4 , is a 25, 35 b i6. 
Light i8 b 9, 19*11, 30 a i5. 
Line 9 a 4, 30. 

Mathematician 3 b 15. 
Mathematics 2 b 19, 3i b 16. 
Matter 3 b I, 18, I2 a 7, 9, b 8, 20, 

I4 a 14, 15, 16,26, i6 a 18, I7 a 27. 
Mean 24 a 4, b i, 3i a n, 19, 35 a 2i. 
Medium I9 a 2o- b 3, 22 b 22, 23 a 15, 

b 7, 26, 

Metaphysician 3 b 16. 

Mind 4 a 3 i, b 2, 22, 5 a is, 1 6, 7 a 4, 
23, 8 b 18, 29, io b i 4 , i 3 b 25, is a 
12, b i6, 29 a 6, 7, io-32 a i4, 32 b 
26, 27, 33 a is. 

Mnemonics 27 b 19. 

Mole 25* 10. 

Movement 4 b 8, 5 a 4, 10, b 3i~7 b 
n, 8 a 34- b 33 io b i7, I2 b i7, 
I5 b 22, I7 a i5, 26 a 2, 5, b 30, 
3i a 6, 32 a is-34 a 2i, 34 b 3i> 32. 

Number 2 a 22, 4 b 24, 6 b 29, 8 b 32- 

9 b i8, 2 5 a i 9 . 
Numerical identity n b 2i, I5 b 7, 

27 a 2, 3I a 23. 

Nutrition, nutritive Ii b 27, I3 a 3i, 
b 5> 7, M a 32, I5 a 2, 23-i6 b 3i, 
34 a 22. 

One, Idea of 4 b 20, 22. Cf. Unity. 
Opinion 27 b 25 } 28 a i8- b 9, 34 a 10, 

Organ Il b 23, I2 b i, 12, I5 b 19, 

l6 a 5, 20 b 22, 29 a 26. 

Orphic poems io b 28. 

Passion (&>^o>) 3 a 17, I4 b 2, 32 a 25, 

33 b 4- 

Passive mind 3o a 24. 
Philippus 6 b 17. 
Plants io b 23, 30, i i b 19, 28, I2 b 3, 

I3 a 25, 33, b i6, I4 a 33, 5 a 2, 

24 a 33, 34 b 2, 35 b i- 
Plato 4 b 1 6, 6 b 26. 
Pleasure I3 b 23, I4 b 3, 31*10, 

34 a 3- 

Potential, Potentially, Potentiality 
2 a 26, I2 a 9, I3 b i8, I4 a i6, I7 a 
6, 2i- b s, 30, I9 b 5, 27 a 6, 
29 a 16, 29, b 8, 30, 30 a 10-21, 
3i a 2. Cf. Powers. 

Powers of soul I3 a i, 33, I4 a 29~ 
I5 a i 3 , I5 a 25,i6 a i9,32 a 25,33 a 
I, 34 a 22-35 b 25- Cf. Potential. 

Practical thinking 7 a 24, 33 a i6, 18. 

Pupil of the eye I3 a 2, 25 a 4, 31*17. 

Pythagoreans 4 a 17, 7 b 22. 

Quicksilver 6 b 19. 

Reflection I9 b 16, 35 a 5- 
Reminiscence 8 b 17. 
Reproduction I5 a 23. 
Respiration 2o b 23, 25. 
Rudder i6 b 26. 

Sailor 6 a 6, I3 a 9. 
Seed 5 b 3, 4, I2 b 26. 

Sensation depends on movement 
l6 b 33; a qualitative alteration 
I5 b 24; involved in being an 
animal I3 b 2, cf. 34 a 3o; always 
true 28 a 1 1 ; sensation involves 


pleasure and pain I3 b 23, cf. I4 b 
4, 34* 3 ; sensation the number 
of the solid (Plato) 4 b 23; is 
what is sensible 3i b 23 ; how it 
differs from knowledge I7 b 
22-8; plants have none 35 b l. 
Cf. Sense. 

Sense, each, relative to a group of 
qualities 26 b 8,25*19; sense 
has two meanings i; a 12. 26*23, 
28 a 6 ; not a magnitude 24* 27 ; 
but a ratio, ib., 26 b 3, 7 ; hence 
injured by strong stimulation 
26* 30, 29* 31 ; is a mean 24* 4 ; 
its work, discrimination 32* 16; 
is what receives form without 
nutter 24 a i8; is the form of 
sensible things 32*3; activity 
of object and of sense identical 
25 b 26; is affected only by the 
quality of its obiect 24 a 23; only 
five senses 24 b 22: how distri 
buted imong animals I4 a 3, I3 b 
4 ; each sense apprehends one 
pair of contraries, except touch 
22 b 23, i8 a i4, 22 b 25; special 
objects of the senses i8 a 1 1, 25* 
30, 27 b 12, 28 b 1 8, 30 b 2g; com 
mon objects i8 a i7, 28 b 22; 
incidental objects i8 a 2O, 2b b 19; 
why do we not perceive the 
senses? I7 a 3; the senses sub 
serve well-being 34 b 24, 35 b 19 ; 
why have we more than one 
sense ? 25 b 4. Cf. Sensation. 

Sense-organ 1 9* 26, 22 b 22, 23 b 20, 
30, 24 a 24, 25 a 3, b 23, 26 b 16, 
35 a i5 18,22, b 15. 

Sight I2 b i9, I3 a i, I8 a 26-i9 b 3, 
2 4 a io, 26 a i 3 , 28*6, 29*3, 35 b 


Signet-ring 24* 19. 

Simple ^c a 26, b 6, 14. Cf. Indivis 
ible, Undivided. 

Sleep I2 a 25. 

Smell I9 a 35, b I, 2i a 7-22 a 7, 24 b 
4, 6, 7, 17, 25*5, 2 6 b 2, 2 9 b 2, 
34 b 20. 

Snub-nosed 29 b 14, 3i b 13. 

Soul, its study a task for physics 
3 a 28 ; thought to be either an 
element or composed of them 5 b 
13; identified with fire (Demo- 
critus) 3 b 3i, 5 a 8, cf. 6 b 17, 9 b 
8; air (Diogenes) 5 a 2i; ex 
halation (Heraclitus) a 25 ; water 
(Hippo) b 2; blood(Critias) b 6; 
the self-moving (Plato), 6 a i, cf. 

b 26 ; a self-moving number 
(Xenocrates) 8 b 32 ; a harmony 
7 b 30 ; found everywhere I i a 8 ; 
Aristotle s definition I2 a 27, b 5, 
I4 a 27; how susceptible of a 
single definition !4 b 2O, cf. I2 b 
4, 2 b 5 ; involves a bo ly of a 
definite kind 1 4 a 22, cf. 7 b 15-26; 
inseparable from its body I3 a 4; 
affection- of soul )( affections of 
animal 2 a g, 3*4 ; soul not moved 
6 a 2-7 b 2, 8 b 15, 30, 11*25; has 
not a place 6 a i6; is that by 
which we live 14* 12 ; cause 
of the living body I5 b 8; holds 
the body together Ii b 8, ib a 8; 
natural bodies are organs of soul 
I5 b 18, 7 b 26 ; nothing dominant 
over soul io b 13; the whole soul 
)( its parts 2 b io, ii a 3O, I3 b l3, 
32 a 2o; not all parts of soul 
belong to all animals I3 b 32, I4 b 
29 ; power of calculation pre 
supposes all the others I5 a 8. cf. 
I3 a 3i, Ii b 29; each successive 
power presupposes its predeces 
sor I4 b 29; reproductive soul 
the first i6 b 25, cf. 5 b 5 ; are the 
parts distinct in local situation? 
I3 b l5,ii b 26; soul is in a sense 
all existing things 3i b 2i; or 
rather their forms b 28, 32*2, 
I7 b 23; soul the place of forms 
29 a 27; alleged derivation of 

Sound 2o a 2i, b 11, 29. 

Species I4 b 22; specific difference, 

identity 2 b 3, ii b 2o, I5 b 7. Cf. 

Speculative knowledge 30*4, 33* 


Spontaneous generation 15*27. 

Squaring 13* 17. 

Substance (ouo-m) 2*23, 24, 10*20, 

12*6, 7, b lo, 19, 14*14. Cf. 


Taste2i a i8, 22 a 8- b 16,26* 14, 31, 

34 b i8, 21, 22, 35 b 22. 
Teaching I7 b n. 
Thales 5 a 19, 11*8. 
Thinking (vorjvis) 7*7, 23, 32, 27 b 

17,27, 30*26, 33*12. 
Thirst I4 b i2. 
Thought (dtdvoia) 15*8, 27 b 14, 33 a 

1 8. 

Time 26 b 24-31, 3o b 8. 
Tongue 2o b 18, 22 b 5, 23* 1 8, 

35 b 25< 

Touch I3 b 4, 6, I4 a 3, b 3, i 5 a 3) 4> 
21*19, 22 b i7-24 a i6, 24 b 25,34* 
I, b i8,35i2, 17, 2i, b 2-4,6, 16. 

Transparent i8 b 4, 28, 30. 

Triangle 2 b 2o, I4 b 3i. 

True 4 a 28, 30* 27, 3i b 10, 32 a 1 1. 

Undivided 26 b 3i, 27* 5, 6, 10. Cf. 

Indivisible, Simple. 
Unity I2 b 8, 13*21. Cf. One. 


Universals I7 b : 
Voice 2o b 5, 32. 

Waking 12*25, b 28. 
Water i6 a 26, 23*25. 
\Vax24 a i9, 35 a 2, 9. 
Weakness, moral 33*3, 34* 14, 
Wish 32 b 5, 33*23, 24, 34*12. 
Writing-tablet 30* I. 







J. I. BEARE, M.A. 







G. R. T. ROSS, M.A., D.PIIIL. 










HAVING now definitely considered the soul, by itself, and 436 a 
its several faculties, we must next make a survey of animals 
and all living things, in order to ascertain what functions 
are peculiar, and what functions are common, to them. What 
has been already determined respecting the soul [sc. by itself] 
must be assumed throughout. The remaining parts [sc. the 
attributes of soul and body conjointly] of our subject must be 
now dealt with, and we may begin with those that come first. 

The most important attributes of animals, whether common 
to all or peculiar to some, are, manifestly, attributes of soul 
and body in conjunction, e.g., sensation, memory, passion, 
appetite and desire in general, and, in addition, pleasure and 
pain. For these 1 may, in fact, be said to belong to all animals. 10 
But there are, besides these, certain other attributes, of which 
some are common to all living things, while others are peculiar 
to certain species of animals. The most important of these 
may be summed up in four pairs, viz. leaking and sleeping, 
youth and old age, inhalation and exhalation, life and death. 
We must endeavour to arrive at a scientific conception of r 
these, determining their respective natures, and the causes of 
their occurrence. 

But it behoves the Physical Philosopher to obtain also 
a clear view of the first principles of health and disease, inas 
much as neither health nor disease can exist in lifeless things. 
Indeed we may say of most physical inquirers, and of those - o 
physicians who study their art philosophically, that while the 
former complete their works with a disquisition on medicine, 
the latter usually base their medical theories on principles 436 b 
derived from Physics. 

1 a 10 raOra, like TOUGHS a ii, refers to all the things enumerated. K<U 
yup (= ctcnim, namque] confirms all from tt 6 to a n. not merely the 
supcraddition of rjdovf) and AI TH;. [ For these also - sc. pleasure and 
pain. Kdd.J 

AK I-S J5 

43 6 b UK SENSU 

That all the attributes above enumerated belong to soul 
and body in conjunction, is obvious ; for they all either imply 
sensation as a concomitant, or have it as their medium. 
5 Some are either affections or states of sensation, others, 
means of defending and safe-guarding it, while others, again, 
involve its destruction or negation. Now it is clear, alike by 
reasoning and observation, that sensation is generated in the 
soul through the medium of the body. 

We have already, in our treatise de Anima, explained the 
nature of sensation and the act of perceiving by sense, and 

10 the reason why this affection belongs to animals. Sensation 
must, indeed, be attributed to all animals as such, for by its 
presence or absence we distinguish essentially between what 
is and what is not an animal. 

But coming now to the special senses severally, we may 
say that touch and taste necessarily appertain to all animals, 
touch, for the reason given in the de A/iima, 1 and taste, 

1 5 because of nutrition. It is by taste that one distinguishes 
in food the pleasant from the unpleasant, so as to flee from 
the latter and pursue the former : and savour in general is an 
affection of nutrient matter. 

The senses which operate through external media, viz. 
smelling, hearing, seeing, are found in all animals which possess 
the faculty of locomotion. To all that possess them they are 

20 a means of preservation ; their final cause being that such 
creatures may, guided by antecedent perception, both pursue 
their food, and shun things that are bad or destructive. But 

437 a in animals which have also intelligence they serve for the 

attainment of a higher perfection. They bring in tidings of 
many distinctive qualities of things, from which the knowledge 
of truth, speculative and practical, is generated in the soul. 

Of the two last mentioned, seeing, regarded as a supply for 

the primary wants of life, and in its direct effects, is the 

5 superior sense ; but for developing intelligence, and in its 

indirect consequences, hearing takes the precedence. The 

faculty of seeing, thanks to the fact that all bodies arc 

coloured, brings tidings of multitudes of distinctive qualities 

of all sorts ; whence it is through this sense especially that 

1 Cf. de An. 434 b 10-24. 

CHAPTER I 437 a 

we perceive the common sensibles, viz. figure, magnitude, 
motion, number : while hearing announces only the distinctive 
qualities of sound, and, to some few animals, those also of 10 
voice. Indirectly, however, it is hearing that contributes most 
to the growth of intelligence. For rational discourse is a cause 
of instruction in virtue of its being audible, which l it is, not 
directly, but indirectly ; since it is composed of words, and 
each word is a thought-symbol. Accordingly, of persons 15 
destitute from birth of either sense, the blind are more 
intelligent than the deaf and dumb. 


Of the distinctive potency of each of the faculties of sense 
enough has been said already. 

But as to the nature of the sensory organs, or parts of the 
body in which each of the senses is naturally implanted, 
inquirers now usually take as their guide the fundamental --o 
elements of bodies. Not, however, finding it easy to co 
ordinate five senses with four elements, they are at a loss 
respecting the fifth sense. But they hold the organ of sight 
to consist of fire, being prompted to this view by a certain 
sensory affection of whose true cause they are ignorant. This 
is that, when the eye is pressed or 2 moved, fire appears to 
flash from it. This naturally takes place in darkness, or when 25 
the eyelids are closed, for then, too, darkness is produced. 

This theory, however, solves one question only to raise 
another ; for, unless on the hypothesis that a person who is in 
his full senses can see an object of vision without being aware 
of it, 3 the eye must on this theory see itself. But then why 
does the above affection not occur also when the eye is at 
rest ? The true explanation of this affection, which will con- 30 
tain the answer to our question, and account for the current 
notion that the eye consists of fire, must be determined in 
the following way : 

1 Plato, Theaet. 2O3 b , had laid down this proposition. The comma 
should precede OKOVOTOS in !l 13. 

2 The phenomenon occurs even without pressure, when the eye is rolled 
voluntarily from side to side in darkness. [ And. Kdd.] 

3 For aladavo^vos here cf. 448 a 26-30. Thucyd. v. 26 alaBavupsvos = 
in full possession of one s faculties . 

13 2 

437 a DK SENSU 

Things which arc smooth have the natural property of 
shining in darkness, without, however, producing light. Now, 
437 b the part of the eye called the black , i.e. its central part, 
is manifestly smooth. The phenomenon of the flash occurs 
only when the eye is moved, because only then could it 
possibly occur that the same one object should become as it 
were two. The rapidity of the movement has the effect of 
making that which sees and that which is seen seem different 
5 from one another. Hence the phenomenon does not occur 
unless the motion is rapid and takes place in darkness. For 
it is in the dark that that which is smooth, e. g. the heads of 
certain fishes, and the sepia of the cuttle-fish, naturally shines, 
and, when the movement of the eye is slow, it is impossible 
that that which sees and that which is seen should appear to 
be simultaneously two and one. But, in fact, the eye sees 

10 itself in the above phenomenon merely as it does so in 
ordinary optical reflexion. 

If the visual organ proper really were fire, which is the 
doctrine of Empcdocles, a doctrine taught also in the Timacns^ 
and if vision were the result of light issuing from the eye as 
from a lantern, why should the eye not have had the power 
of seeing even in the dark ? It is totally idle to say, as the 

15 Timaeus docs, that the visual ray coming forth in the dark 
ness is quenched. What is the meaning of this quenching of 
light? That which, like a fire of coals or an ordinary flame, 
is hot and dry is, indeed, quenched by the moist or cold ; but 
heat and dryness are evidently not attributes of light. Or if 
they are attributes of it, but belong to it in a degree so slight 

;o as to be imperceptible to us, we should have expected that in 
the daytime 2 the light of the sun should be quenched when 
rain falls, and that darkness should prevail in frosty weather. 
Flame, for example, and ignited bodies are subject to such 
extinction, but experience shows that nothing of this sort 
happens to the sunlight. 

Empcdocles at times seems to hold that vision is to be 
explained as above stated by light issuing forth from the eye, 

- ; e. g., in the following passage : 

1 Cf. Tim. 45 D. 

- Probably for rf we should read y(. n<ff ypcpav is emphatic. 


As when one who purposes going abroad prepares 

a lantern, 

A gleam of fire blazing through the stormy night, 
Adjusting thereto, to screen it from all sorts of winds. 

transparent sides, 

Which scatter the breath of the winds as they blow, 
While, out through them leaping, the fire, i. e. all the :,o 

more subtile part of this, 

Shines along his threshold with incessant beams : 
So [Divine love] embedded the round " lens , [viz.] the 43 8 a 

primaeval fire fenced within the membranes. 
In [its own] delicate tissues ; 

And these fended off the deep surrounding flood, 
While leaping forth l the fire, i.e. all its more subtile part . 

Sometimes he accounts for vision thus, but at other times 
he explains it by emanations from the visible objects. 

Democritus, on the other hand, is right in his opinion that 5 
the eye is of water ; not, however, when he goes on to explain 
seeing as mere mirroring. The mirroring that takes place 
in an eye is due to the fact that the eye is smooth, and 
it really has its seat not in the eye which is seen, but in that 
which sees. For the case is merely one of reflexion. But it 
would seem that even in his time there was no scientific 
knowledge of the general subject of the formation of images 10 
and the phenomena of reflexion. It is strange too, that it 
never occurred to him to ask why, if his theory be true, the 
eye alone sees, while none of the other things in which images 
are reflected do so. 

True, then, the visual organ proper is composed of water, 
yet vision appertains to it not because it is so composed, but 
because it is translucent a property common alike to water 
and to air. But water is more easily confined and more easily 15 
condensed - than air ; wherefore it is that the pupil, i. e. the 
eye proper, consists of water. That it does so is proved by 

1 Diels reads fiuWfcop, allowed to pass through (subject at, sc. Movm). 

a Evni\r]TOT(pov 438*15 is wrong. The rendering magis spissa , 

denser , slurs the tv- to save the sense. We should probably read 

(VnTroArjTrrorfpov, for which cf. 2I3 U 27 (V(nr<i\(in!3avoLT(S [rot/ (i/pa] f v TUIS 

K\(\l/v8pais. Cf. also 9i4 b n. It is false (cf. 386 8- 10) to say that water 
is evTTtXr/roVfpoi/ TOV upof, but it is more easily secluded in a capsule. 
Thurot after Alexander suggests ttuTroXr/TTTdrfpoj , in opposition to 5i<;- 

438 a 


facts of actual experience. The substance which flows from 
eyes when decomposing is seen to be water, and this in 
undeveloped embryos is remarkably cold and glistening. In 

20 sanguineous animals the white of the eye is fat and oily, 
in order that the moisture of the eye may be proof against 
freezing. Wherefore the eye is of all parts of the body the 
least sensitive to cold : no one ever feels cold in the part 
sheltered by the eyelids. The eyes of bloodless animals are 
covered with a hard scale which gives them similar protection. 

2 ; It is, to state the matter generally, an irrational notion that 
the eye should see in virtue of something issuing from it ; 
that the visual ray should extend itself all the way to the 
stars, or else go out merely to a certain point, and there 
coalesce, as some say, with rays which proceed from the 
object. It would be better to suppose this coalescence l to 
take place in the fundament of the eye itself. But even 
this would be mere trifling. For what is meant by the 

30 coalescence of light with light? Or how is it possible? 

Coalescence does not occur between any two things taken 

at random. And how could the light within the eye coalesce 

438 b with that outside it ? For the environing membrane comes 

between them. 

That without light vision is impossible has been stated 
elsewhere ; - but, whether the medium between the eye and 
its objects is air or light, vision is caused by a process through 
this medium. 

. Accordingly, that the inner part of the eye consists of water 
is easily intelligible, water being translucent. 

Now, as vision outwardly is impossible without [extra- 
organic] light, so also it is impossible inwardly [without light 
within the organ]. There must, therefore, be some translucent 
medium within the eye, and, as this is not air, it must be 
water. The soul or its perceptive part is not situated at the 
external surface of the eye, but obviously somewhere within : 

]C whence the necessity of the interior of the eye being trans 
lucent, i. e. capable of admitting light. And that it is so is 

- organic fusion : a growing of things into one. The nearest 
term for this is coalescence in its strict or Latin sense. 

- Cf. dc An, 4i8 b 1 seqq. 


plain from actual occurrences. It is matter of experience that 
soldiers wounded in battle by a sword slash on the temple, 
so inflicted as to sever 1 the passages of [i.e. inward from] 
the eye, feel a sudden onset of darkness, as if a lamp had 
gone out ; because what is called the pupil, i. e. the translucent, 
which is a sort of inner lamp, is then cut off [from its connexion 15 
with the soul]. 

Hence, if the facts be at all as here stated, it is clear that 
if one should explain the nature of the sensory organs in this 
way, i. e., by correlating each of them with one of the four 
elements, we must conceive that the part of the eye im 
mediately concerned in vision consists of water, that the part 
immediately concerned in the perception of sound consists JQ 
of air, and that the sense - of smell consists of fire. (I say the 
sense of smell, not the organ.) For the organ of smell is only 
potentially that which the sense of smell, as realized, is actually ; 
since the object of sense is what causes the actualization of 
each sense, so that it (the sense) must (at the instant of 
actualization) be (actually) that which before (the moment 
of actualization) it was potentially. Now, odour is a smoke- 
like evaporation, and smoke-like evaporation arises from fire. 
This also helps us to understand why the olfactory organ has 2$ 
its proper seat in the environment of the brain, for cold matter 
is potentially hot. In the same way must the genesis of the 
eye be explained. Its structure is an offshoot from the brain, 
because the latter is the inoistcst and coldest of all the bodily 

The organ of touch proper consists of earth, and the 30 
faculty of taste is a particular form of touch. This explains 439 a 
why the sensory organ of both touch and taste is closely 
related to the heart. For the heart, as being the hottest of all 
the bodily parts, is the counterpoise of the brain. 

This then is the way in which the characteristics of the 
bodily organs of sense must be determined. 5 

1 [Read perhaps (after Bywater, /. P. 28. 242) ooare rp^vat, so that 
the passages are cut. Edd.J 

2 The organs of the other senses are regarded here as being actually 

y, &c., but the organ of smell as being only potentially rrvpus (the 
being actually so). Like the brain, near which it is situated, it 
is actually cold, and only potentially hot. 

43ga DE SKNSU 


Of the scnsibles corresponding to each sensory organ, viz. 
colour, sound, odour, savour, touch, we have treated in the de 
Anlma^ in general terms, having there determined what their 
function is, and what is implied in their becoming actualized 

10 in relation to their respective organs. We must next consider 
what account we are to give of any one of them ; what, for 
example, we should say colour is, or sound ^ or odour ^ or savour ; 
and so also respecting [the object of] touch. We begin with 

Now, each of them may be spoken of from two points of 
view, i. e., cither as actual or as potential. We have in the 
dc Aiiima - explained in what sense the colour, or sound, 
regarded as actualized [for sensation], is the same as, and in 

i; what sense it is different from, the correlative sensation, the 
actual seeing or hearing. The point of our present discussion 
is, therefore, to determine what each sensible object must be in 
itself, in order to be perceived as it is in actual consciousness. 
We have 15 already in the de Anima stated of Light that it 
is the colour of the Translucent, [being so related to it] 
incidentally ; for whenever a fiery element is in a translucent 

20 medium its presence there is Light ; while the privation of it 
is Darkness. But the Translucent , as we call it, is not 
something peculiar to air, or water, or any other of the bodies 
usually called translucent, but is a common nature and 
power, capable of no separate existence of its own, but residing 
in these, and subsisting likewise in all other bodies in a greater 

2$ or less degree. As the bodies in which it subsists must have 
some extreme bounding surface, so too must this. Here, 4 
then, we may say that Light is a nature inhering in the 
Translucent when the latter is without determinate boundary. 
But it is manifest that, when the Translucent is in determinate 

1 Cf. de An. 418* 26 seqq., 41 9 b 5 seqq., 42 i a 7 seqq., 422 a 8 seqq., 422 * 
17 seqq., for Aristotle s treatment of these sensibles respectively. 

l de An, 425^ 25~426 b 8. 

;1 eoaTrf,* : the apodosis begins at } \n\v oui> a 26. For Light and Colour 
cf. de An. 418* 26 seqq. 

4 Referring back to protasis a 18. 


bodies, its bounding extreme must be something real ; and that 
colour is just this something we are plainly taught by facts 
colour being actually either at the external limit, or being 30 
itself that limit, in bodies. Hence it was that the Pytha 
goreans named the superficies of a body its hue . for * hue , 
indeed, lies at the limit of the body ; but the limit of the body 
is not a real thing ; ] rather \ve must suppose that the same 
natural substance which, externally, is the vehicle of colour 
exists [as such a possible vehicle] also in the interior of the 

Air and water, too [i.e. as well as determinately bounded 439!) 
bodies], are seen to possess colour ; for their brightness is of 
the nature of colour. But the colour which air or sea presents, 
since the body in which it resides is not determinately bounded, 
is not the same when one approaches and views it close by as 
it is when one regards it from a distance ; whereas in deter- 5 
minate bodies the colour presented is definitely fixed, unless, 
indeed, when the atmospheric environment causes it to change. 
Hence it is clear that that in them which is susceptible of 
colour is in both cases the same. It is therefore the Trans 
lucent, according to the degree to which it subsists in bodies 
(and it does so in all more or less), that causes them to 
partake of colour. But since the colour is at the extremity of 10 
the body, it must be at the extremity of the Translucent 
in the body. Whence it follows that we may define colour as 
the limit of the Translucent in determinately bounded body. 
For whether we consider the special class of bodies called 
translucent, as water and such others, or determinate bodies, 
which appear to possess a fixed colour of their own, it is at the 
exterior bounding surface - that all alike exhibit their colour. 

Now, that which when present in air produces light may be 
present also in the Translucent which pervades determinate 15 
bodies ; or again, it may not be present, but there may be 
a privation of it. Accordingly, as in the case of air the 
one condition is light, the other darkness, in the same way 

1 Thus it differs from TO eo-^iroi/ TOV ftuxfxivovs, which /V a real thing ( a 28). 
The limit of body is its geometrical surface, and merely quantitative, but 
colour is a quality. In a real thing, quality and quantity are combined. 

- In 439 14 the comma should come after iTni/^fi, not after 

439 b DE SENSU 

the colours White and Black are generated in determinate 

We must now treat of the other colours, reviewing the 
several hypotheses invented to explain their genesis. 

20 i. It is conceivable that the White and the Black should 
be juxtaposed in quantities so minute that [a particle of] 
either separately would be invisible, though the joint product 
[ of two particles, a black and a white] would be visible ; and 
that they should thus have the other colours for resultants. 
Their product could, at all events, appear neither white nor 
black ; and, as it must have some colour, and can have neither 

_>5 of these, this colour must be of a mixed character in fact, 
a species of colour different from either. Such, then, is 
a possible way of conceiving the existence of a plurality of 
colours besides the White and Black ; and we may suppose 
that [of this plurality ] many are the result of a [numerical] 
ratio ; for the blacks and whites may be juxtaposed in the 
ratio of 3 to 2, or of 3 to 4, or in ratios expressible by other 
numbers; while some may be juxtaposed according to no 

30 numerically expressible ratio, but according to some relation 
of excess or defect in which the blacks and whites involved 
would be incommensurable quantities ; and, accordingly, we 
may regard all these colours [viz. all those based on numerical 
ratios] as analogous to the sounds that enter into music, 1 
and suppose that those involving simple numerical ratios, like 
the concords in music, may be those generally regarded as 
most agreeable ; as, for example, purple, crimson, and some 
few such colours, their fewness being due to the same causes 

440 a which render the concords few. The other compound colours 

may be those which are not based on numbers. Or it may 
be that, while all colours whatever [except black and white] 
are based on numbers, some are regular in this respect, 
others irregular ; and that the latter [though now supposed 
to be all based on numbers], whenever they are not pure, 

1 E*ct b 32 refers to rals (rv^coviais h 31, implying a wider meaning for 
this term there than it has in b 33, where it = the great concords, dis 
tinctively called by musical writers ai o-vp.<f>a>vim (viz. the octave, fourth, 
and fifth), which have simple ratios. We must remember that musical 
sounds (though all involve \6yos) are not all concords. These musical 
sounds in general are those referred to as no\\as b 27. The concords are 
comparatively few (440* 2). 


owe this character to a corresponding impurity 1 in [the 
arrangement of] their numerical ratios. This then is one r 
conceivable hypothesis to explain the genesis of intermediate 

2. Another 2 is that the Black and White appear the one 
through the medium of the other, giving an effect like that 
sometimes produced by painters overlaying a less vivid upon 
a more vivid colour, as when they desire to represent an 
object appearing under water or enveloped in a haze, and 10 
like that produced by the sun, which in itself appears white, 
but takes a crimson hue when beheld through a fog or a cloud 
of smoke. On this hypothesis, too, a variety of colours may 
be conceived to arise in the same way as that already 
described ; for between those at the surface and those under 
neath a definite ratio might sometimes exist ; in other cases 
they might stand in no determinate ratio. To [introduce 
a theory of colour which would set all these hypotheses aside, 
and] say with the ancients that colours are emanations, and i; 
that the visibility of objects is due to such a cause, is absurd. 
For they must, in any case, explain sense-perception through 
Touch ; so that it were better to say at once that visual 
perception is due to a process set up by the perceived object 
in the medium between this object and the sensory organ ; 

1 By the new hypothesis, all colours are fv a^idp-ols^ but all need not be 
TfTny/jifvai tv dpidp.o is, and only these are KaOapa t, i. e. pleasant, or piu e, 

colours. TotaiTflS goes with (ivat 44O :l 6, not with yiyvfo-Qat. yiyvftrOdi 

is here used again as it has been above, 439 b 22, so as to contain the 
predicate. The colours which are not Kadapai arise , owing to their not 
being such (i.e. not being Ttraypcvai) in their numerical basis. All are tv 
apifytoty, but not all rera-y/ifV<u fv tipiflpnis : the same construction as in 
440* 3-4. The (wras a 5 points the antithesis between the xp (U on ^ ie 
new and on the old hypothesis. To take roiavras with yiyvfa-Om would 
involve a contradiction in terms. Hence attempts at correction like 
Biehl s rols nvroiV ante upiO. Better than this would have been the 
insertion of roiourots before rotavras. But the construction is quite natural 
without change, if rotavrns be construed with emit and understood as 
above = rt Tiiyptvas eV apiQpots. The UTOKTOI which turn out impure 
would thus be those in which a single, uniform ratio is not observed 
throughout all the mixture, but in which the ingredients are some mixed 
in one ratio, others in another, so that the ratios themselves are mixed, 
or impure. The rfraypfvai or Kadapai XP" U are * ne opposite. So 

2 On this second colour-hypothesis we are not dealing with infmi- 
tesimally small amounts of black and white : we may now have surfaces 
of any extent, a black above and a white below, or I icc i ers<i. 

440 a DE SENSU 

due, that is, to contact [with the medium affected], not to 
emanations. 1 

20 If we accept the hypothesis of juxtaposition, we must assume 
not only invisible magnitude, but also imperceptible time, in 
order that the succession in the arrival of the stimulatory 
movements may be unperceived, and that the compound 
colour seen may appear to be one, owing to its successive parts 
seeming to present themselves at once. On the hypothesis 
of superposition, however, no such assumption is needful : the 
stimulatory process produced in the medium by the upper 
colour, when this is itself unaffected, will be different in kind 

25 from that produced by it when affected by the underlying 
colour. Hence it presents itself as a different colour, i.e. as 
one which is neither white nor black. So that, if it is im 
possible to suppose any magnitude to be invisible, and we 
must assume that there is some distance from which every 
magnitude is visible, this superposition theory, too [i. e. as 
well as Xo. 3 infra], might pass as a real theory of colour- 
mixture. Indeed, in the previous case also there is no 
reason why, to persons at a distance from the juxtaposed 
blacks and whites, some one colour should not appear to 

.-,> present itself as a blend of both. [But it would not be 
so on a nearer view], for it will be shown, in a discussion to 
be undertaken later on, that there is no magnitude absolutely 

3. 3 There is a mixture of bodies, however, not merely such 
440 b as some suppose, i. e. by juxtaposition of their minimal parts, 
which, owing to [the weakness of our] sense, are imperceptible 
by us. but a mixture by which they [i. e. the matter of 
which they consist] are wholly blent together by interpenetra- 
tion, as we have described it in the treatise on Mixture. 4 

1 \Ve see from 435* 18 how far Aristotle was prepared to go with the 
theory which would reduce all sensations to modes of Touch. Alexander s 
reading (f? acfr/ /cal r<ur) seems to give a simpler sense than that of Biehl, 
but does not suit the TTIIVT^S ( in any case ) of a 17. The insertion of // 
arose from thinking that Aristotle could in no sense admit tKpj i to 
a participation in visual activity. 

* Cf. de Sensu vii. 448" 24 - b 14. 

* The apodosis to fi* fVrt begins with <JXXu on 440 13. 

4 Cf. 328* 5 seqq. where piis and avvQcots are distinguished and 
severally explained. Cf. Joachim, Aristotle s Conception of Chemical 
Combination, Journal oj Philology, xxix. 72 86. 


where we dealt with this subject generally in its most com 
prehensive aspect. For, on the supposition we are criticizing, 
the only totals capable of being mixed are those which are 5 
divisible into minimal parts, [e.g. genera into individuals] as 
men, horses, or the [various kinds of] seeds. For of mankind 
as a whole the individual man is such a least part ; of horses 
[as an aggregate], the individual horse. Hence by the juxta 
position of these we obtain a mixed total, consisting [like 
a troop of cavalry] of both together ; but we do not say that 
by such a process any individual man has been mixed with 
any individual horse. Not in this way, but by complete 10 
interpenetration [of their matter], must we conceive those 
things to be mixed which are not divisible into minima; and 
it is in the case of these that natural mixture exhibits itself in 
its most perfect form. We have explained already in our 
discourse On Mixture how such mixture is possible. This 
being the true nature of mixture, it is plain that when bodies 
are mixed their colours also are necessarily mixed at the same 
time; and [it is no less plain] that this is the real cause 15 
determining the existence of a plurality of colours not super 
position or juxtaposition. For when bodies are thus mixed, 
their resultant colour presents itself as one and the same at 
all distances alike ; not varying as it is seen nearer or farther 

Colours will thus, too [as well as on the former hypotheses], 
be many in number on account of the fact that the ingredients 
may be combined with one another in a multitude of ratios ; 20 
some will be based on determinate numerical ratios, 1 while 
others again will have as their basis a relation of quantitative 
excess or defect not expressible in integers. And all else that 
was said in reference to the colours, considered as juxtaposed 
or superposed, may be said of them likewise when regarded 
as mixed in the way just described. 

Why colours, as well as savours and sounds, consist of species 
determinate [in themselves] and not infinite [in number] is a 
question which we shall discuss hereafter. 2 25 

1 The TU (v apidfiols b 20 includes under it the cases of those merely 
Adyta in some sort of numerical ratio and of those eV evXoyiVrotr Xdyoir. 
* de Sensu, ch. vi. 445 21 29, 446* 16-20. 

440 b DE SENSU 


We have now explained what colour is. and the reason why 
there are many colours ; while before, in our work de Anima, 1 
we explained the nature of sound and voice. We have next 
to speak of Odour and Savour, both of which are almost the 
same physical affection, although they each have their being 

30 in different things. 2 Savours, as a class, display their nature 
more clearly to us than Odours, the cause of which is that the 
441 a olfactory sense of man is inferior in acuteness to that of the 
lower animals, and is, when compared with our other senses, 
the least perfect of all. Man s sense of Touch, on the contrary, 
excels that of all other animals in fineness, and Taste is 
a modification of Touch. 

Now the natural substance water per sc tends to be tasteless. 
But [since without water tasting is impossible] either (a) we 
must suppose that water contains in itself [uniformly diffused 
through it] the various kinds of savour, already formed, though 
5 in amounts so small as to be imperceptible, which is the doctrine 
of Empedocles ; or (b) the water must be a sort of matter, 
qualified, as it were, to produce germs of savours of all kinds, 
so that all kinds of savour are generated from the water, though 
different kinds from its different parts ; or else (c) the water is 
in itself quite undifferentiated in respect of savour [whether 
developed or undeveloped], but some agent, such for example 
as one might conceive Heat or the Sun to be, is the efficient 
cause of savour. 

10 (a) Of these three hypotheses, the falsity of that held by 
Empedocles is only too evident. For we see that when peri- 
carpal fruits 3 are plucked [from the tree] and exposed in the 

1 de An. 41 9 b 5 seqq. (sound), and 420 * 5 seqq. (voice). 

- i. e. not merely (v u\\u>y(Vfi (cf. ch. v. ad init.} but also in different physi 
cal media and vehicles, oo-p} being in air and water, x^/ios- in water. Cf. 
ch. v. ad init. The meaning is clear from Theophr. De Cans. PL VI. i. I 
\V[JLUS fJLtv i] TOII rjpov dia rov vypov dir]6i](Tis VTTO 8(pp.ov . . . ocrpfj de TOV fv 
\vp.d) \l(bi le^. eyxvfjLov] rjpov (V ro> diafpavd TOVTO yap KOIVOV ae pop Km vdaros 
K<ii axeSbv TO civroirdQos tori ^u/xoO rt nai o(rp.fjf^ OVK (v rols avrols df cicarcpoir. 
This book of Theophrastus should be read with the present chapter of 
Arist. de Sensu, and also with ch. v. Cf. de Sensu v. ad init. 442 29, 
and443 b is. 

3 ircpiKaprriwv. Aristotle often (cf. Ideler, Meteor, ii. p. 424 quod ntpi- 
hoc et aliis in locis ab Aristotele vocatur, Kapnos a Graecis 


sun, or subjected to the action of fire, their sapid juices l are 
changed by the heat, which shows that their qualities are not 
due to their drawing anything from the water in the ground, 
but to a change which they undergo within the pericarp itself ; 
and we see, moreover, that these juices, when extracted and 
allowed to lie, instead of sweet become by lapse of time harsh 15 
or bitter, or acquire savours of any and every sort ; and that, 
again, by the process of boiling or fermentation 2 they are 
made to assume almost all kinds of new savours. 

(b) It is likewise impossible that water should be a material 
qualified to generate all kinds of Savour germs [so that 
different savours should arise out of different parts of the 
water] ; for we see different kinds of taste generated from the 
same water, having it as their nutriment. 

(c) It remains, therefore, to suppose that the water is changed 30 
by passively receiving some affection from an external agent. 
Now, it is manifest that water does not contract the quality of 
sapidity from the agency of Heat alone. For water is of all 
liquids the thinnest, thinner even than oil itself, though oil, 
owing to its viscosity, is more ductile than water, the latter --5 
being uncohesive in its particles ; whence water is more 
difficult than oil to hold in the hand without spilling. But 
since perfectly pure water does not, when subjected to the 
action of Heat, show any tendency to acquire consistency, 
we must infer that some other agency than heat is the cause 
of sapidity. For all savours [i. c. sapid liquors] exhibit 

a comparative consistency. Heat is, however, a co-agent in 
the matter. 

Now the sapid juices found in pericarpal fruits evidently 441 b 
exist also in the earth. Hence many of the old natural philo 
sophers assert that water has qualities like those of the earth 
through which it flows, a fact especially manifest in the case 
of saline springs, for salt is a form of earth. Hence also when 

vocatum est ) uses irfpiKdpniov for what ordinary (ireeks would have 
called Kupnos, e.g. the grape is for him a TrepiKiipmov. Cf. Theoph. J)e dins. 
PI. I. l6. I xapTTos 5 eort ro <TvyK(ip.(i>ov (nr(pp.a ^tra TOU TrepiKapniov. 

1 xvp "* in a 12 = xi Xour, but there is no need to adopt this reading. 

3 Boiling would not be adequate as a rendering, and fyetr&u 
is applied to new wine, or must, 38o b 31-2. Aristotle is here probably 
thinking of such changes as are undergone by, e. g., the juice of the grape 
when extracted and left to ferment. 

44 i b UE SENSU 

r liquids are filtered through ashes, a bitter substance, the taste 
they yield is bitter. There are many wells, too, of which some 
are bitter, others acid, while others exhibit other tastes of all 

As was to be anticipated, therefore, it is in the vegetable 
kingdom that tastes occur in richest variety. For, like all 
things else, the Moist, by nature s law ? is affected only by its 
contrary ; and this contrary is the Dry. Thus we see why 
10 the Moist is affected by Fire, which, as a natural substance, is 
dry. Heat is, however, the essential property of Fire, as 
Dryness is of Earth, according to what has been said in our 
treatise 1 on the elements. Fire and Earth, therefore, taken 
absolutely as such, have no natural power to affect, or be 
affected by, one another ; nor have any other pair of sub- 
15 stances. Any two things can affect, or be affected by, one 
another only so far as contrariety to the other resides in cither 
of them. 

As, therefore, persons washing Colours or Savours in a liquid 
cause the water in which they wash to acquire such a quality 
[as that of the colour or savour], so nature, too, by washing the 
Dry and Earthy in the Moist, and by filtering the latter, that 
is, moving it on by the agency of heat through the dry and 
earthy, imparts to it a certain quality. This affection, wrought 
20 by the aforesaid Dry in the Moist, capable of transforming 
the sense of Taste from potentiality to actuality, is Savour. 
Savour brings into actual exercise the perceptive faculty 
which pre-existed only in potency. The activity of sense- 
perception in general is analogous, not to the process of 
acquiring knowledge, but to that of exercising knowledge 
already acquired. 

That Savours, either as a quality or as the privation 
-5 of a quality, belong not to every form of the Dry but to the 
Nutrient, we shall see by considering that neither the Dry 
without the Moist, nor the Moist without the Dry. is nutrient. 
For no single element, but only composite substance, con 
stitutes nutriment for animals. Now, among the perceptible 
elements of the food which animals assimilate, the tangible are 

1 Cf. de Gen. ct Con; 328 b 33 seqq. for the affection of contraries by their 
contraries, and for what is here said of Fire and Earth. 


441 b 

the efficient causes of growth and decay ; it is qua hot or cold 
that the food assimilated causes these ; for the heat or cold is 3 
the direct cause of growth or decay. It is qua gustable, how 
ever, that the assimilated food supplies nutrition. For all 442 a 
organisms are nourished by the Sweet [i. e. the gustable 
proper], either by itself or in combination with other savours. 
Of this we must speak with more precise detail in our work on 
Generation : l for the present we need touch upon it only so far 
as our subject here requires. Heat causes growth, and fits the 
food-stuff for alimentation ; it attracts [into the organic 5 
system] that which is light [viz. the sweet], while the salt and 
bitter it rejects because of their heaviness. In fact, whatever 
effects external heat produces in external bodies, the same are 
produced by their internal heat in animal and vegetable organ 
isms. Hence it is [i.e. by the agency of heat as described) 
that nourishment is effected by the sweet. The other 
savours are introduced into and blended in food [naturally] 
on a principle analogous to that on which the saline or the 10 
acid is used artificially, i. e. for seasoning. These latter are 
used because they counteract the - tendency of the sweet to 
be too nutrient, and to float on the stomach. 

As the intermediate colours arise from the mixture of white 
and black, so the intermediate savours arise from the Sweet 
and Bitter ; and these savours, too, severally involve either 3 a 
definite ratio, or else an indefinite relation of degree, between 
their components, cither having certain integral numbers at the , - 
basis of their mixture, and, consequently, of their stimulative 
effect, or else being mixed in proportions not arithmetically 
expressible. The tastes which give pleasure in their com 
bination are those which have their components joined in 
a definite ratio. 

1 de Gen. An. 762 * 12 seqq. Cf. also de (Jen. ct L\rr. 335"* lo seqq 
and de part. An. 650* 3 seqq. 

2 Biehl s UVTI irai/Twi> is not legitimately translatable, though if it could 
be taken with r<u>a it might be rendered these (viz. the saline and acid) 
as substitutes for all Nature s variety . Read avrurrravTio, without comma 
before ro>. For avTunruv with dat. cf. 873** 20. 

3 Thurot s suggestion of ft rj for drj has been adopted. KUTU \6yov and 
TW /ifiXXoi/ Km T]Trov are here as before consistently opposed to one another ; 
they are the alternatives. KfT<iXo-yo/ = i in determinate ratio. Cf.439 b 29-30 
Kfjra /^eV Xoyoi/ fjirjdfva, KnO vn(po\fji> de riva *ai eAXft^if iiuvfintrpor, the 
passage to which a 12 o>rr;rf/) T<\ ,Y/>u>/^mi refers. 

44 2 a DE SENSU 

The sweet taste alone is Rich, [therefore the latter may be 
regarded as a variety of the former], while [so far as both 
imply privation of the Sweet] the Saline is fairly identical with 
the Bitter. Between the extremes of sweet and bitter come 
the Harsh, the Pungent, the Astringent, and the Acid. Savours 
and Colours, it will be observed, contain respectively about the 

20 same number of species. For there are seven l species of 
each, if, as is reasonable, we regard Dun [or Grey] as a variety 
of Black (for the alternative is that Yellow should be classed 
with White, as Rich with Sweet) ; while [the irreducible 
colours, viz.] Crimson, Violet, leek-Green, and deep Blue, 
come between White and Black, and from these all others 

35 are derived by mixture. 

Again, as Black is a privation of White in the Translucent, 
so Saline or Bitter is a privation of Sweet in the Nutrient 
Moist. This explains why the ash of all burnt things is 
bitter; for the potable [sc. the sweet] moisture has been exuded 
from them. 

30 Dcmocritus 2 and most of the natural philosophers who treat 

442 b of sense-perception proceed quite irrationally, for they represent 

all objects of sense as objects of Touch. Yet, if this is really 

so, it clearly follows that each of the other senses is a mode of 

Touch ; but one can see at a glance that this is impossible. 

1 a 20-25. ^ e have seven colours if \ve either merge Dun (or Grey) 
in Black or Yellow in White. If we merged both, we should have only 
six : if we allowed both to stand out, eight. So we have seven savours if 
we merge Rich in Sweet or Saline in Bitter. The clause Acin-crm . . . 
yXvKtos should be printed as parenthetical, indicating the other way of 
obtaining the number seven The seven colours are thus Crimson, Violet, 
Green, Blue, Black, \Vhite, with either Yellow or Dun. <j>mus is cither Dun 
or Grey. In spite of Susemihl s computation, fnra is right. Cf. Theophr. 
Cans. PL vi. i. 2 ra 6 tldrirvv xi /io>i> a>r piv (is apiOpov airo&ovvat padtov, olov 
yXvKis Xnrapus avar/;po9 (Trpvfyvbs dptfiVS dX/ivpoy nixpbs ovs. Here he gives 
eight species, but in vi. 4. I he writes : at 6c tSt ai TOOV \vp.vv eVra doKovatv 
civai Kadiintp Kal TO>V OCT-/LZOOJ/ /cat TO>J> ^pw/iaVcoi , TOITO 6e Civ TIS rov aXfivpov 
ov% erepov ridr/ rov niKpov KaBdnfp Kal TO <j>aibi> TOV /JeAafOf. tav 6e ^u>pi^i) 
avpflaivci TOITOV oy8uoi> twai. ^ator is treated as a shade of black and 
dA/u>poV as a variety of niKpov, while av66v and \inapov, though closely 
connected with Xcixop and y\vKv, are separate qualities and counted in 
the seven. Cf. ffovXfrai yap 6 llT(iXep.mos cnra \pa)p.ara dvai rtjs ipt8of, 
Olympiod. in Meteor, lib. iii. and Ideler, Meteor, ii. p. 138. 

* It is amazing how Thurot can have regarded the following passage 
as irrelevant. If Democritus explanation of Taste by the shapes of 
atoms were correct, Aristotle s theory of it would fall to the ground. Hence 
he had to grapple with it. 


Again, they treat the percepts common to all senses as 
proper to one. For [the qualities by which they explain 5 
taste, viz.] Magnitude and Figure, Roughness and Smoothness, 
and, moreover, the Sharpness and Bluntness found in solid 
bodies, are percepts common to all the senses, or if not to all, 
at least to Sight and Touch. This explains why it is that 
the senses are liable to err regarding them, while no such 
error arises respecting their proper sensibles ; e. g. the sense 
of Seeing is not deceived as to Colour, nor is that of Hearing 
as to Sound. 

On the other hand, they reduce the proper to common 10 
sensibles, as Democritus does with White and Black ; for he 
asserts that the latter is [a mode of the] rough, and the former 
[a mode of the] smooth, while he reduces Savours to the atomic 
figures. Yet surely no one sense, or, if any, the sense of Sight 
rather than any other, can discern the common sensibles. But 
if we suppose that the sense of Taste is better able to do so, 
then since to discern the smallest objects in each kind is what 15 
marks the acutest sense Taste should have been the sense which 
best perceived the common sensibles generally, and showed 
the most perfect power of discerning figures in general. 

Again, all the sensibles involve contrariety ; e. g. in Colour 
White is contrary to Black, and in Savours Bitter is contrary 
to Sweet ; but no one figure is reckoned as contrary to any . o 
other figure. Flse, to which of the possible polygonal figures 
[to which Democritus reduces Bitter] is the spherical figure 
[to which he reduces Sweet] contrary ? 

Again, since figures are infinite in number, savours also 
should be infinite ; [the possible rejoinder that they are so, 
only that some are not perceived cannot be sustained] for 
why should one savour be perceived, and another not ? 

This completes our discussion of the object of Taste, i.e. 
Savour; for the other affections of Savours are examined in 25 
their proper place in connection with the natural history 
of Plants. 

C 2 

442 b 



Our conception of the nature of Odours must be analogous to 
that of Savours; inasmuch as the Sapid Dry 1 effects 2 in air 
and water alike, but in a different province of sense, precisely 
what the Dry effects 3 in the Moist of water only. We custom- 

30 arily predicate Translucency of both air and water in common ; 
443 a but it is not qua translucent that either is a vehicle of odour, 
but qua possessed of a power of washing or rinsing [and so 
imbibing] the Sapid Dry ness. 

For the object of Smell exists not in air only : it also exists 
in water. This is proved by the case of fishes and testacea, 
5 which are seen to possess the faculty of smell, although water 
contains no air (for whenever air is generated within water 
it rises to the surface), and these creatures do not respire. 
Hence, if one were to assume that air and water are both moist, 
it would follow that Odour is the natural substance consisting 
of the Sapid Dry diffused in the Moist, and whatever is of this 
kind would be an object of Smell. 

That the property of odorousness is based upon the Sapid 
may be seen by comparing the things which possess with those 

13 which do not possess odour. The elements, viz. Fire, Air, 
Earth, Water, are inodorous, because both the dry and the 
moist among them are without sapidity, unless some added 
ingredient produces it. This explains why sea-water possesses 
odour, for [unlike elemental water] it contains savour and 
clryness. Salt, too, is more odorous than natron, as the oil 

15 which exudes from the former proves, for natron is allied to 
[ elemental ] earth more nearly than salt. Again, a stone is 
inodorous, just because it is tasteless, while, on the contrary, 
wood is odorous, because it is sapid. The kinds of wood, too, 
which contain more [ elemental ] water are less odorous than 
others. Moreover, to take the case of metals, 4 gold is inodorous 

1 In b 29 >ip6i> is to be read, not vy/>oV. 
* Sc. for the sense of smell. 
3 Sc. for the sense of taste. 

To understand Aristotle s point of view as to metals here one 
should read Timaeus 58 D to 59 B, and Theophr. ntpi Xi ^uv, I v 
p.i><i)v TO. ptv t(TTiv vS(nos t Tii d( yfjs vdaros pev TCI p.fra\- 
apyvpot KU\ xpv&vs KU\ ruXXti. Cf. Theophr. de Cans. PI. 

CHAPTER V 443 a 

because it is without taste, but bronze and iron are odorous ; 
and when the [sapid] moisture l has been burnt out of them, 
their slag is, in all cases, less odorous [than the metals 
themselves]. Silver and tin are more odorous than the one 
class of metals, less so than the other, inasmuch as they are 
watery 2 [to a greater degree than the former, to a less degree 20 
than the latter]. 

Some writers look upon Finn id exhalation, which is a com 
pound of Earth and Air, as the essence of Odour. [Indeed 
all are inclined to rush to this theory of Odour. 3 ] Heraclitus 
implied his adherence to it when he declared 4 that if all exist 
ing things were turned into Smoke, the nose would be the 
organ to discern them with. All 5 writers incline to refer odour 
to this cause [sc. exhalation of some sort], but some regard it 25 
as aqueous, others as fumid, exhalation ; while others, again, 
hold it to be either. Aqueous exhalation is merely a form of 
moisture, but fumid exhalation is, as already remarked, com 
posed of Air and Earth. The former when condensed turns 
into water ; the latter, into a particular species of earth. Now, 
it is unlikely that odour is either of these. For vaporous 3 
exhalation consists of mere water [which, being tasteless, is 
inodorous] ; and fumid exhalation cannot occur in water at 

vi. 3. 2. Metals belong to what Plato calls TO \VTOV ytvos TOV \<8aTos ; the 
water (of rivers, &c.) to TO vypw. We must remember that water (the 
<jToix(ir>v) is inodorous and tasteless : that therefore the substance into 
which it enters is likewise inodorous and tasteless, according to the pro- 
portion of such water in it, and so with yfj. We must carefully distinguish 
the v8a>p and yy as elements from the common earth and water, which are 
mixtures. Cf. av nr] TI f/iyvvfttvov noirj 443* II. 

1 TO vypov : sc. TO tyxi ^nv : all developed xvpos has TO vypov for its vehicle, 
but \vp )s (i. e. TO cyxvpov frpov) is the base of 0070} : hence the result here 
mentioned. For when the vypov is burnt away, the fyx^/iov frpnv has 
nothing to wash in. Cf. 442* 29. 

vo<iT(i)8^ is short for rwv p.n\\nv TMV ft TJTTOV u&iTcoSij. They are more 
odorous than e.g. gold, because they have more common [or less ele 
mental ] water in their composition than this, less odorous than bronze 
and iron, for they contain less common [or more elemental ] water. 

3 an ...oo-fi^f being contradictory of what precedes ard follows is 
rightly bracketed by Biehl after Thurot. The text is still astray, as Christ s 
(e/ri ToCro) b 25 gives an unsupported use of e nufrfptivrtn. 

4 The OTI is certainly spurious. Cf. the on of Thucydides iv. 37 (yvovt 
. . . ort . . . dtacpduptjaofjLtvois) which has lately been given up on the 
evidence of papyri, and the anacoluthia cured. Cf. Oxyr. Pap. 16 (in 
JJodleian). For a similar o>? . . . on cf. 454 a 15-16. 

3 The apodosis to eVet begins with uAX a 2q. 

443a SENSU 

all, though, as has been before stated, aquatic creatures also 
have the sense of smell. 

443 b Again, the exhalation theory of odour is analogous to the 
theory of emanations. If, therefore, the latter is untenable, 
so, too, is the former. 

It is clearly conceivable that the Moist, whether in air (for 
air, too, is essentially moist) or in water, should imbibe the in- 
5 fluence of, and have effects wrought in it by, the Sapid Dryness. 
Moreover, if the Dry produces in moist media, i.e. water 1 and 
air, an effect as of something washed out in them, it is mani 
fest that odours must be something analogous to savours. 
Nay, indeed, this analogy is, in some instances, a fact [registered 
in language] ; for odours as well as savours are spoken of as 
\<ipniigent, sweet, Jiarsh, astringent, rich [ = savoury^ ; and one 
might regard fetid smells as analogous to bitter tastes ; which 
explains why the former are offensive to inhalation as the latter 
are to deglutition. It is clear, therefore, that Odour is in both 
water and air what Savour is in water alone. This explains 
1 5 why coldness and freezing render Savours dull, and abolish 
odours altogether ; for cooling and freezing tend to annul the 
kinetic heat which helps to fabricate sapidity. 2 

There are two species of the Odorous. For the statement 
of certain writers that the odorous is not divisible into species 
is false ; it is so divisible. We must here define the sense in 
which these species are to be admitted or denied. 

One class of odours, then, is that which runs parallel, as has 
jo been observed, to savours : to odours of this class their 
pleasantness or unpleasantness belongs incidentally. For 
owing to the fact that Savours are qualities of nutrient matter, 
the odours connected with these [e. g. those of a certain food] 
are agreeable as long as animals have an appetite for the food, 
but they are not agreeable to them when sated and no longer 
in want of it ; nor are they agreeable, cither, to those animals 
that do not like the food itself which yields the odours. 
25 Hence, as we observed, these odours are pleasant or unpleasant 
incidentally, and the same reasoning explains why it is that 
they are perceptible to all animals in common. 

1 It seems necessary to read (as Thurot suggests) V T vdart after rroiet. 

2 For explanation see above, chap. iv. 44i b 18. 

CHAPTER V 443 b 

The other class of odours consists of those agreeable l in 
their essential nature, e. g. those of flowers. For these do 
not in any degree stimulate animals to food, nor do they 
contribute in any way to appetite ; their effect upon it, if any, 
is rather the opposite. For the verse of Strattis ridiculing 3 
Use not perfumery to flavour soup, 
contains a truth. 

Those who nowadays introduce such flavours into bever 
ages deforce our sense of pleasure by habituating us to them. 444 a 
until, from two distinct kinds of sensations combined, pleasure 
arises as it might from one simple kind. 

Of this species of odour man alone is sensible ; the other, 
viz. that correlated with Tastes, is, as has been said before, 
perceptible also to the lower animals. And odours of the 5 
latter sort, since their pleasureableness depends upon taste, 
are divided into as many species as there are different tastes ; 
but we cannot go on to say this of the former kind of odour, 
since its nature is agreeable or disagreeable per se. The reason 
why the perception of such odours is peculiar to man is found 
in the characteristic state of man s brain. For his brain is TO 
naturally cold, and the blood which it contains in its vessels 
is thin and pure but easily cooled (whence it happens that 
the exhalation arising from food, being cooled by the coldness 
of this region, produces unhealthy rheums) ; therefore it is 
that odours of such a species have been generated for human 
beings, as a safeguard to health. This is their sole function, 5 
and that they perform it is evident. For food, whether dry or 
moist, though sweet to taste, is often unwholesome ; whereas 
the odour arising from what is fragrant, that odour which is 
pleasant in its own right, is, so to say, always beneficial to 
persons in any state of bodily health whatever. 

For this reason, too, the perception of odour [in general] is 
effected through respiration, not in all animals, but in man 20 
and certain other sanguineous animals, e.g. quadrupeds, and 
all that participate freely in the natural substance air ; because 
when odours, on account of the lightness of the heat in them, 

1 443 b 28-30. Aristotle is thinking only of agreeable smells, though he 
should have thought of disagreeable ones also. 

444 a r>K SENSU 

mount to the brain, the health of this region is thereby 
promoted. For odour, as a power, is naturally heat-giving. 
25 Thus 1 Nature has employed respiration for two purposes: 
primarily for the relief thereby brought to the thorax, 
secondarily for the inhalation of odour. For while an animal 
is inhaling, odour moves in 2 through its nostrils, as it were 
from a side-entrance. 

But the perception of the second class of odours above 
described [does not belong to all animals, but] is confined to 
30 human beings, because man s brain is. in proportion to his 
whole bulk, larger and moistcr than the brain of any other 
animal. This is the reason of the further fact that man 
alone, so to speak, among animals perceives and takes pleasure 
in the odours of flowers and such things. For the heat and 
stimulation set up by these odours are commensurate with the 
444 b excess of moisture and coldness in his cerebral region. On all 
the other animals which have lungs, Nature has bestowed their 
due perception of one of the two kinds of odour [i.e. that con 
nected with nutrition] through 3 the act of respiration, guarding 
against the needless creation of two organs of sense ; for in the 
fact that they respire the other animals have already sufficient 
provision for their perception of the one species of odour 
5 only, as human beings have for their perception of both. 

But that creatures which do not respire have the olfactory 
sense is evident. For fishes, and all insects as a class, have, 
thanks to the species of odour correlated with nutrition, 
a keen olfactory sense of their proper food from a distance, 
10 even when they are very far away from it ; such is the case 
with bees, and also with the class of small ants, which some 
denominate knipes. Among marine animals, too, the murex 
and many other similar animals have an acute perception of 
their food by its odour. 

It is not equalh* certain what the organ is whereby they so 

is perceive. This question, of the organ whereby they perceive 

odour, may well cause a difficulty, if we assume that smelling 

. . . KiY;<ru il) 25 28sliould perhapscome after <mr$/70-if 444^7. 

2 The middle entrance to the stage was (says Pollux) reserved for the 
principal character. Here odour plays a subordinate part. 

3 Thurot s dia TOV with nno^fdoxfv (for which he might quote 657* 7 
(V yap iv/ nvarrvorjs r; m-rffijffis rot? r^ot tr p-vicrfjpas) has been adopted. 


444 b 

takes place in animals only while respiring (for that this is the 
fact is manifest in all the animals which do respire), whereas 
none of those just mentioned respires, and yet they have 
the sense of smell unless, indeed, they have some other sense 
not included in the ordinary five. This supposition is, however, 20 
impossible. For any sense which perceives odour is a sense 
of smell, and this they do perceive, though probably not in 
the same way as creatures which respire, but when the latter 
are respiring the current of breath removes something that is 
laid like a lid upon the organ proper (which explains why 
they do not perceive odours when not respiring) ; while in 
creatures which do not respire this is always off: just as some 25 
animals have eyelids on their eyes, and when these are not 
raised they cannot see, whereas hard-eyed animals have no 
lids, and consequently do not need, besides eyes, an agency to 
raise the lids, but see straicrhtwav [without intermission! 

o * L 

from the actual moment l at which it is first possible for 
them to do so [i. e. from the moment when an object first 
comes within their field of vision]. 

Consistently with what has been said above, not one of the 
lo\vcr animals shows repugnance to the odour of things 
which are essentially ill-smelling, unless one of the latter is .>o 
positively pernicious. They are destroyed, however, by these 
things, just as 1 human beings are ; 3 i.e. as human beings get 
headaches from, and arc often asphyxiated by, the fumes of 
charcoal, so the lower animals perish from the strong fumes 
of brimstone and bituminous substances ; and it is owing to 
experience of such effects that they shun these. For the 445 a 
disagreeable odour in itself they care nothing whatever (though 
the odours of many plants are essentially disagreeable), un 
less, indeed, it has some effect upon the taste of their food. 

1 The expression in the Greek of Hiehl s text is strange. It might also 
be rendered In virtue of the mere possession of the faculty of seeing : 
f| avTov TOV dwciTov oi/rof, sc. opiiv. But, lids or no lids, this would be so, 
and with tiki s-, as here, it is more natural to make fV refer to the initial 
moment of time. SwaTtw must agree with (I\Q\. govern) bpav understood, 
the construction being i>6vs avrov TOV (o^i/) dwaTov OITOS. 

2 ojioiW, i. e. not by the odour proper but by the mephitis or gas. 

3 The construction would be improved if *ac were transposed to before 
Ka$u7Tfp b 3i, and if only a comma were read after 7ro\Xu<af ^32, OVTMS 
answering Kadantp. Then the *ai KT\. would be explanatory of the O/ 

So it has here been translated. 

445 a DE SENSU 

5 The senses making up an odd number, and an odd number 
having always a middle unit, the sense of smell occupies in 
itself as it were a middle position between the tactual senses, 
i.e. Touch and Taste, and those which perceive through 
a medium, i. e. Sight and Hearing. Hence the object of smell, 
too. is an affection of nutrient substances (which fall within 

10 the class of Tangibles), and is also an affection of the audible 
and the visible ; whence it is that creatures have the sense 
of smell both in air and water. Accordingly, the object of 
smell is something common to both of these provinces, i. e. it 
appertains both to the tangible on the one hand, and on the 
other to the audible and translucent. 1 Hence the propriety 
of the figure by which it has been described by us as an 
immersion or washing of dryness in the Moist and Fluid. Such 

IT then must be our account of the sense in which one is or is 
not entitled to speak of the odorous as having species. 

The theory held by certain of the Pythagoreans, that some 
animals are nourished by odours alone, is unsound. For, in 
the first place, we see that food must be composite, since the 
bodies nourished by it are not simple. This explains why 
waste matter is secreted from food, either within the organisms, 

20 or, as in plants, outside them. But since 2 even water by itself 
alone, that is, when unmixed, will not suffice for food for 
anything which is to form a consistency must be corporeal , 
it is still much less conceivable that air should be so cor- 
porealized [and thus fitted to be food]. But, besides this, 
we see that all animals have a receptacle for food, from 
which, when it has entered, the body absorbs it. Now, the 

25 organ which perceives odour is in the head, and odour enters 
with the inhalation of the breath ; so that it goes to the 
respiratory region. It is plain, therefore, that odour, qua 
odour, does not contribute to nutrition ; that, however, it is 

t indicates that as above, a 9-10, the objects, so here the media 
are referred to. In a 12 cirrrw and aKouo-ro) are virtually the media of Touch 
(for there is a sense in which Touch has a medium) and Hearing, as 
8ia(f)<iv(~i is that of Seeing. 

2 a 20. For crt 5 we should read ore! & , the apodosis to which begins ert 
noXv a 22. fn\ ov&e ... en ?roXv TJTTOV frames the a fortiori argument. 
No new point is introduced at a 22, but only the conclusion of the argument 
begun by Trpwrov piv 445 a 17. To this Trpwroi/ pei> the npos 8e TOVTOIS 
a 23 corresponds. 


serviceable to health is equally plain, as well by immediate 
perception as from the arguments above employed ; so that 
odour is in relation to general health what savour is in the 3 
province of nutrition and in relation to the bodies nourished. 

This then must conclude our discussion of the several organs 445 b 
of sense-perception. 


One might ask : if every body is infinitely divisible, are 
its sensible qualities Colour, Savour, Odour, Sound, Weight, 5 
Cold or Heat, [Heaviness or] Lightness, Hardness or Softness 
also infinitely divisible? Or, is this impossible 1 ? 

[One might well ask this question], because each of them is 
productive of sense-perception, since, in fact, all derive their 
name [of sensible qualities ] from the very circumstance of 
their being able to stimulate this. Hence, [if this is so] both 
our perception of them should likewise be divisible to infinity, 
and every part of a body [however small] should be a perceptible 10 
magnitude. For it is impossible, e.g., to see a thing which 
is white but not of a certain magnitude. 

Since 2 if it were not so, [if its sensible qualities were not 
divisible, part passn with body], we might conceive a body 
existing but having no colour, or weight, or any such quality ; 
accordingly not perceptible at all. For these qualities are the 
objects of sense-perception. On this supposition, every per 
ceptible object should be regarded as composed not of 
perceptible [but of imperceptible] parts. Yet it must [be really 
composed of perceptible parts], since assuredly it does not i; 
consist of mathematical [and therefore purely abstract and 
non-sensible] quantities. Again, by what faculty should we 
discern and cognize these [hypothetical real things without 
sensible qualities] ? Is it by Reason ? But they are not 
objects of Reason ; nor docs reason apprehend objects in space, 

1 Biehl should have printed /} 5i mToi/ the second member of the 
7ro/Mrt as a question. 

2 b 7. Trotr/Tt/coj/ yap is continued by ct yap b 1 1. If (as Alex. 1 10, 7, \V. 
thinks) the first part of the argument (ending p) Trnabv 5e) had concluded 
for the negative, this second yap would be absurd. 

445 b DE SENSU 

except when it acts in conjunction with sense-perception. At 
the same time, if this be the case [that there are magnitudes, 
physically real, but without sensible quality], it seems to tell 
in favour of the atomistic hypothesis ; for thus, indeed, [by 
accepting this hypothesis], the question [with which this chapter 
begins] might be solved [negatively]. Hut it is impossible [to 

jo accept this hypothesis]. Our views on the subject of atoms 
are to be found in our treatise on Movement. 1 

The solution of these questions 2 will bring with it also the 
answer to the question why the species of Colour, Taste, Sound, 
and other sensible qualities are limited. For in all classes of 
things lying between extremes the intermediates must be 
limited. But contraries are extremes, and every object of 

25 sense-perception involves contrariety: e.g. in Colour, White 
x Black: in Savour, SweetxBittcr, and in all the other sensibles 
also the contraries are extremes. Now, that which is continuous 
is divisible into an infinite number of unequal parts, but into 
a finite number of equal parts, while that which is not per sc 
continuous is divisible into species which are finite in number. 
Since then, the several sensible qualities of things are to be 

; ,o reckoned as species, while continuity always subsists in these, 1 5 
we must take account of the difference between the Potential 
and the Actual. 4 It is owing to this difference that we do 

1 See Phys. vi. 1-2 1231 !l 2i-232 a 25). 

2 i. c. the two questions of the anoxia. Aristotle in the preceding 
arguments has only (as Thurot observes) developed the affirmative side of 
the dnopia, leaving the negative (?) ddvvarov) undeveloped. He has argued 
directly for the affirmative in b 7-11 (TTOITJTIKOV . . . 5e), and indirectly in 
b 1 1-20 ft yap . . . Kivijo-eats. There was no need to argue for the negative: 
for common sense does not require to be convinced that we cannot see 
or otherwise perceive the infinitesimally small. So we say, but this view 
now Aristotle takes up and corrects, by his theory that we can do so, 
potentially. There is no reason to suppose that Aristotle did argue here 
for the negative side, and that a portion of the text has been lost. 

h 30. rotTois, sc. TO IS 7r<i6((Tiv ws ("idfCTii 1 . All alffBijTa fall under cither 
T. > crvi f\fs or TO pt} Ka6 ni To crvvf^f s. The latter is divisible into etdi? which 
partake of its continuity (sc. of rj Kara <n>/ifc/3i7KM? <rwe\(ia}. The TrdQrj, 
being ("ify, also possess this continuity : but, if so, why are not infinite 
simal ^fyfOi] alff6r]Tii perceived, their qualities having (in virtue of this 
continuity 17 Kara avfj.) been also divided together with the substrate ? To 
answer this question, it is necessary to refer to the distinction between 
the potential and the actual. 

4 He aims at showing (a) that the minute parts of a rrd^/tza (e.g. 
a colour), when divided <mi o-v^f^Kos with its substrate, may become 
indeed imperceptible eW/rycia, but always (unless they perish with their 


not [actually] see its ten-thousandth part in a grain of millet. 446 a 
although sight has embraced the whole grain within its scope ; 
and it is owing to this, too, that the sound contained in 
a quarter-tone escapes notice, and yet one hears the whole 
strain, 1 inasmuch as it is a continuum ; but the interval 
between the extreme sounds [that bound the quarter-tone] 
escapes the ear [being only potentially audible, not actually]. 
So, in the case of other objects of sense, extremely small con 
stituents are unnoticed ; because they are only potentially not 5 
actually [perceptible, e. g.] visible, unless - when they have been 
parted from the wholes. So the foot-length too exists potenti 
ally 3 in the two-foot length, but actually only when it has been 
separated from the whole. But objective increments so small 
as those above might well, if separated from their totals, 
[instead of achieving actual existence] be dissolved in their 
environments, like a drop of sapid moisture poured out into 
the sea. But even if this were not so [sc. with the objective 
magnitude], still, since the [subjective] increment of sense- 10 

substrate, like a drop in the ocean) remain perceptible (as the particle to 
which each part cleaves ismo^rovjfiiWi^ei ;and()that when, by aggregation 
of particles or otherwise, these potential perceptibles again become actual, 
their flfy reappear limited as before : never having been really changed in 
quality, and therefore never multiplied, for the d8rj as such have not been 
divided. To this b 23-30 (TTIIV . . . rovrois) is prefatory. 

1 fie Xof, see Chappell, p. 87 : we must not here think of a melody, or a series 
of notes, in a scale but of the continuous raising or lowering (aTroruoru-) of 
the tone of a voice or string. The fi/frrtf (here -= quarter tone) was the 
conventional unit of measurement. It is itself an interval, but so small 
that the parts of which it consists are not distinguishable by the ear. 
TO rov p. Trpof rots (<r% Vovs 00. = the interval consisting of the difvis. 

2 Reading (with EMY) /ur) \ojp\s /. 

3 He wishes to remove a possible ground of misunderstanding. The foot- 
length too is, like these small parts, only potentially existent while in the 
two-foot length: but, unlike them, when separated it is (supply vnupxa, not 
(vvndpxft) then first actually existent, while these may not even then be 
actually existent, but may be dissolved, &c. But Aristotle s present point 
(introduced by ov ^v <i\X ) is that magnitudes stand on a different footing 
from Trufl;;, and must be distinguished in the mV0/r<i (which are both). The 
mere vrrfpo^ aiadqcrcux has at no time any existence except as in a whole, 
and so its object a correspondingly small rra^/za mffGrjrov actually exists 
only in a substrate. It has not, like a magnitude (e. g. i; 7ro<Wu), a 
separate existence. But unless the substrate of it perishes, it is always 
potentially perceptible ; and when the small parts are reaggregated, it 
will become actually perceptible again in the total. There is great pro 
bability in Prof. Bywater s emendation dtaipcdetVi? (sc. rfj fiuroSi). 17 nodiaiu 
is here the unit ; and not this but the Sinovs is what really requires bisection. 
To make fii(p*0ero-u = separated from = xa>pt<r0flo-u, is not quite satisfactory. 

446 a 


perception is not perceptible l in itself, nor capable of separate 
existence (since it exists only potentially in the more distinctly 
perceivable whole of sense-perception), so neither will it be 
possible to perceive [actually] its correlatively small object [sc. 
its quantum of iru0j/ma or sensible quality] when separated from 
the object-total. But yet this [small object] is to be considered 
as perceptible: for it is both potentially so already [i.e. even 
when alone], and destined to be actually 2 so when it has 

15 become part of an aggregate. Thus, therefore, we have 
shown that some magnitudes and their sensible qualities escape 
notice, and the reason why they do so, as well as the manner 
in which they are still perceptible or not perceptible in such 
cases. Accordingly then, when these [minutely subdivided] 
sensibles have once again become aggregated in a whole in 
such a manner, relatively to one another, as to be perceptible 
actually, and not merely because they are in the whole, but 
even apart from it, it follows necessarily [from what has been 
already stated 3 ] that their sensible qualities, whether colours 

20 or tastes or sounds, are limited in number. 

One might ask : do the objects of sense-perception, or the 
movements proceeding from them ([since movements there 
are,] in whichever of the two ways [viz. by emanations or by 
stimulatory Kivrjo-is] sense-perception takes place), when these 
are actualized for perception, always arrive first at a spatial 
middle point [between the sense-organ and its object], as Odour 
evidently does, and also Sound ? For he who is nearer [to the 
odorous object] perceives the Odour sooner [than he who is 

25 farther away], and the Sound of a stroke reaches us some time 
after it has been struck. Is it thus also with an object seen, 
and with Light ? Empedocles, for example, says that the Light 
from the Sun arrives first in the intervening space before itcomes 

1 There is no need to read ruVdqrucq if we think of the just noticeable 
differences of sensation in modern * Psychophysik . Indeed alaOrjriK^ 
would not suit the sense here, but rather give rise to a tautology. 

2 a 14. Magnitudes (like the foot-length) actually exist only when 
apart from their wholes ; but niidrj have no such actual existence apart 
from the ptytdrj in which they inhere : their actual existence only comes 
about when the objects to which they belong are or become large enough to 
be actually perceived. Hence there is no discrepancy between this place and 
a 5-7 above, where aiad/?ra as magnitudes are spoken of. 

J Sc. in 445 b 25-29. What they were potentially, in their latent state, 
they show when actualized in an aggregate. 


to the eye, or reaches the Earth. This might plausibly seem 
to be the case. For whatever is moved [in space], 1 is moved 
from one place to another ; hence there must be a corre 
sponding interval of time also in which it is moved from 30 
the one place to the other. But any given time is divisible 446 b 
into parts ; so that we should assume a time when the sun s 
ray was not as yet seen, but was still travelling in the middle 

Now, even if it be true that the acts 2 of hearing and 
1 having heard , and, generally, those of perceiving and 
having perceived , form co-instantaneous wholes, 3 in other 
words, that acts of sense-perception do not involve a process 
of becoming, but have their being none the less without 
involving such a process ; 4 yet, just as, [in the case of sound], 5 
though the stroke which causes the Sound has been already 
struck, the Sound is not yet at the ear (and 5 that this last is 
a fact is further proved by the transformation which the letters 
[viz. the consonants as heard] undergo [in the case of words 
spoken from a distance], implying that the local movement 
[involved in Sound] takes place in the space between [us and 
the speaker] ; for the reason why [persons addressed from 
a distance] do not succeed in catching the sense of what is 
said is evidently that the air [sound wave] in moving towards 
them has its form changed) [granting this, then, the 
question arises] : is the same also true in the case of Colour 
and Light? For certainly it is not true that the beholder 10 
sees, and the object is seen, in virtue of some merely abstract 
relationship between them, such as that between equals. 
For if it were so, there would be no need [as there is] that 
either [the beholder or the thing beheld] should occupy some 

1 We must here bear in mind that there a~e other kinds of KIVIJO-IS 
besides locomotion ($pa) ; sae below 446 b 28. 

8 The fvfpyciat of these mo-drjo-ct? are instantaneous, yet their stimuli 
move in a medium and take time. Is the case the same with Seeing, and 
Light ? The apodosis to KU\ d b 2 begins below at ap* o^ b 9, but is 
prefaced by the clause &<rnfp . . . CIKOJ} b 5-6, to which the OTO> of b 9 refers. 

3 annv <3/ia = all at once. The smallest tvipycia of an mad^ais is 
perfect in itself, anuv is best taken as ace. of inner object after the 

4 Cf. Phys. 6. 258^ 17, de Coelo, A. 280 27. 

6 b 6 &i]\ol to b 9 atpa is parenthetical, and would have been placed in 
a note by a modern writer. 

446 b 


particular place ; since to the equalization of things their 
being near to, or far from, one another makes no difference. 

Now this [travelling through successive positions in the 
medium] may with good reason take place as regards Sound 

1 5 and Odour, for these, like [their media] Air and Water, are 
continuous, but the movement 1 of both is divided into parts. 
This too is the ground of the fact that the object which the 
person first in order of proximity hears or smells is the same 
as that which each subsequent person perceives, while yet it is 
not 2 the same. 

Some, indeed, raise a question also on these very points ; 
they declare it impossible that one person should hear, or see, 
or smell, the same object as another, urging the impossibility 

20 of several persons in different places hearing or smelling [the 
same object], for the one same thing would [thus] be divided 
from itself. The answer is that, in perceiving the object which 
first set up the motion e.g. a bell, or frankincense, or fire 
all perceive an object numerically one and the same ; while, of 
course, in the special object perceived they perceive an object 
numerically different for each, though specifically the same for 
all ; and this, accordingly, explains how it is that many persons 
together see, or smell, or hear [the same object]. These things 

25 [the odour or sound proper] are not bodies, but an affection or 
process of some kind (otherwise this [viz. simultaneous per 
ception of the one object by many] would not have been, as it 
is, a fact of experience), though, on the other hand, 3 they each 
imply a body [as their cause]. 

But [though sound and odour may travel,] with regard to 
Light the case is different. For Light has its raison d etre in 
the being 4 [not becoming] of something, but it is not a move- 

1 All sensibles, therefore x//-o(/;or and oo>t/}, are continuous quantities, cf. 
449 a 20 seqq., capable of infinite subdivision. KIITJO-IS is essentially con 
tinuous for Aristotle, that is it is divisible els t dtiuperd. The KiV^o-tr, or 
stimulus-movement, of sound and odour propagates itself from part to 
part of its medium, and so is divided among the parts successively 
traversed by it. 

3 The senses in which it is and is not are explained just below b 21-25. 

3 oW (if correct) 446 b 26 somewhat alters the point of view given at 
oure b 25. 

4 For what follows cf. 4i8 b 2o-26. The reading TO> emu = ( owing to the 
fact that something is (not becomes) * With ro> evelvm there would be 
a distinct allusion to the irvpudt s rt, and the Tni/unam, of 439 a i9: TO 


ment. 1 And in general, even in qualitative change the case is 
different from what it is in local movement [both being different 
species of KiVrjcris]. Local movements, of course, 2 arrive first 30 
at a point midway before reaching their goal (and Sound, it is 
currently believed, is a movement of something locally moved), 
but we cannot go on to assert this [arrival at a point midway] 447 a 
in like :i manner of things which undergo qualitative change. 
For this kind of change may conceivably take place in a thing 
all at once, without one half of it being changed before the 
other; e.g. it is conceivable that water should be frozen 
simultaneously in every part. But still, for all 4 that, if the 
body which is heated or frozen is extensive, 5 each part of it 
successively is affected by the part contiguous, while the part 
first changed in quality is so changed by the cause itself 5 
which originates the change, and thus the change throughout 
the whole need not take place coinstantaneously and all at 
once. Tasting would have been as smelling now is, if we 

would be nearly the same in sense. TO> tlvai x yiyvtcrtiai : there 
is no process involved. </>o>r (or 0umo>uW) is, for Aristotle, not a KiVqatv 
in any sense not even an dXXotaxn?. For even some dXXotoxmy may 
travel, when the medium is extensive, as the illustrations show ; but 
illumination does not. 

1 The re . . . xai following ovdc is impossible to translate except 
by a periphrasis, e.g. We must not even couple qualitative change 
with local movement, as if they were similar in the respect under 
discussion ; i.e. we must distinguish the obvious travelling of the one, and 
the possible simultaneousness of the change in the other. 

2 tv\uy<as = as the name (/>opi implies, or ex 77 termini. For the kinds 
of Kivrjffts see 406* 12. Plato, I annen. 13 P., had distinguished XXoudat? 
and (fiopd. 

3 ovKfri o/iouo? : i. e. with the same universality as in the case of <J)opu. 
For some <iXXoid>o-eiv are instantaneous, though some are not. But for his 
having denied that (/>o>? is a Ku^ais we might suppose him in the sequel to 
mean that it belongs to the former class of Ki^<r<ir. However, the use of 
ftvai precludes its being a KiV/jair, for emu x yiyvtadai, and therefore 
X Kuetatfm in all its forms. So Alexander (p. 133, 10 \Vendland) under 
stands Aristotle to mean. The reference to ciAXenW^ seems intended 
to show that as this can be simultaneous so a fortiori can (^amo^o s-. which 
is not a Kivrjats but depends on tivai. The attempt to regard Aristotle here 
as having meant that fas is a special kind of dXXotWt? is benevolent, but 
creates great confusion in the passage. Ziaja has tried to make out 
that both here and \r\de Aninui the controversy with Empedocles is inter 
polated and spurious. It is disappointing, to the Aristotelean that 
is all. 

4 ov p.t)v uXX . Though the simultaneity of riXXo/axrif is conceivable, it is 
not necessary. 

5 That this cannot affect the case of light appears from de Animn, 

PN rj 

447 a DE SENSU 

lived in a liquid medium, and perceived [the sapid object] at 
a distance, before touching it. 

Naturally, then, 1 the parts of media 2 between a sensory 

10 organ and its object are not all affected at once except in the 

case of Light [illumination], for the reason y above stated, and 

also in the case of seeing, 4 for the same reason ; for Light 

is an efficient cause of seeing. 


Another question respecting sense-perception is as follows: 
assuming, as is natural, that of two [simultaneous] sensory 
stimuli the stronger always tends to extrude the weaker [from 
consciousness], is it conceivable or not that one should be 
able 3 to discern t] two objects coinstantaneously in the same 
5 individual time ? The above assumption explains why persons 
do not perceive what is brought before their eyes, if they are 
at the time deep in thought, or in a fright, or listening to 
some loud noise. This assumption, then, must be made, and 
also the following : that it is easier to discern each object of 
sense when in its simple form than when an ingredient in 

1 We should have expected S/} (marking, as usual, the conclusion) not 
after et Aoywr. So Alexander quoting ( eGAoyws 1 5r}, $170-1 ), but Uiehl 

does not notice this. 

2 MI* = Tovrutv a. The genitive is partitive, depending on nuird. Alex 

ander wrongly makes o>i> refer to ra mVdqrci. /ierai ToG ni(T0r)Tr}piov p. 

ToG ala-0. Kn\ TO>J/ utVflr/roof, a construction regular in Aristotle. Cf. 440* 18. 
There should be a comma, not a full stop, after fiprjpevoi , on TOV opuv 
as well as Vl roG </>&>ror being under the regimen of n\r )i>. 
* That is, the reason given 446 b 27 (T tlvai n 0o>v VrtV). 

4 The effect of \P^ a on the &</>"* is the stimulus of seeing. Cf. 
43O a l6 TO <j)u>s noid ra dvrd/jifi ovra ^pto/iarn (vcpyfia ovra. If one asks 
how Aristotle would reconcile the proposition in 438^ 4 fj dta TOVTOV Ktvyvis 
((TTiv r; Trotof CTu TO opav with the doctrine here, that light is not a Kivrjvts and 
that xpupa does not locally move towards the eye (see 446 9), what is the 
answer? Every Kivrjais is cv xi )tlv V ( 2 35 a IJ ) anc l e ver y XP l>l/of s diaipfTM 
(ibid.). How then does this nitons not travel in space? Viderit ipse 

5 The usual device for distinguishing dvixxrOai and tV& xfardm has been 
adopted : but it is not easy to believe that the former should be sound 
here. The two are never elsewhere so combined in Aristotle. 

6 alvQavtadai here and generally in this chapter = discern : for the two 
objects must be kept distinct in perception, while perceived coinstan- 
taneously. mrr0q<nr is a dvvapis KPITIKIJ. 


a mixture ; easier, for example, to discern wine when neat than 
when blended, and so also honey, and [in other provinces] 
a colour, or to discern the nctc 1 by itself alone, than [when 
sounded with the hypatc\ in the octave ; the reason being - 
that component elements tend to efface [the distinctive 
characteristics of] one another. Such is the effect [on one 
another] of all ingredients of which, when compounded, some 
one thing is formed. 

If, then, the greater stimulus tends to expel the less, it 
necessarily follows that, when they concur, this greater should 
itself too be less distinctly perceptible than if it were alone, 
since the less by blending with it has removed some of its 
individuality, according to our assumption that simple objects 
are in all cases more distinctly perceptible. 

Now, if the two stimuli are equal but heterogeneous, no -5 
perception of either will ensue ; they will alike efface one 
another s characteristics. But in such a case the perception of 
either stimulus in its simple form is impossible. Hence either 
there will then be no sense-perception at all, or there will 
be a perception compounded of both and differing from either. 
The latter is what actually seems to result from ingredients 
blended- together, whatever may be the compound in which 
they are so mixed. 

Since, then, from some concurrent [sensory stimuli] a re 
sultant object is produced, while from others no such resultant 
is produced, and of the latter sort are those things which belong :,o 
to different sense provinces (for only those things are capable of 
mixture whose extremes are contraries, and no one compound 447 b 
can be formed from, e. g., White and Sharp, except indirectly, 
i.e. not as a concord is formed of Sharp and Grave); there 
follows logically the impossibility of discerning such con 
current stimuli coinstantaneously. For we must suppose that 
the stimuli, when equal, tend alike to efface one another, since 5 

1 Net? (= vc( ur)) and hyfiatc were respectively the highest and the 
lowest notes in the octave. Although hyfatc is the lowest string [of the 
lyre] in point of pitch and sound, it is the "highest" in the Greek sense, 
which is as to length. Nete on the contrary is highest as to sound, but is 
"lowest" when compared in length to any other. Chappell, History of 
Music , p. 36. So D. H. Monro, Modes of Ancient Greek Music, p. 31. 

- rSiv KfpavvvfjLtv<i)v, i.e. blended in the manner referred to 444 3-12, or, 
as we should perhaps say, chemically. 

D 2 

447 b 

no one [form of stimulus] results from them ; while, if they 
are unequal, the stronger alone is distinctly perceptible. 

Again, 1 the soul would be more likely to perceive coinstan- 
taneously, with one and the same sensory act, two things 
in the same sensory province, such as the Grave and the 
Sharp in sound ; for the sensory stimulation in this one 
province is more likely to be unitemporal than that involving 

10 two different provinces, as Sight and Hearing. But it is 
impossible to perceive two objects coinstantaneously in the 
same sensor}- act unless they have been mixed, [when, how 
ever, they are no longer two], for their amalgamation involves 
their becoming one, and the sensory act related to one object 
is itself one, and such act, when one, is, of course, coin- 
stantaneous with itself. Hence, when things are mixed we 
of necessity perceive them coinstantaneously : for we perceive 
them by a perception actually one. For an object numerically 
one means that which is perceived by a perception actually 
one, whereas an object specifically one means that which is 

1 5 perceived by a sensory act potentially one [i.e. by an h cpycia 
of the same sensuous faculty]. If then the actualized percep 
tion is one, it will declare its data to be one object ; they 
must, therefore, have been mixed. Accordingly, when they 
have not been mixed, the actualized perceptions which perceive 
them will be two ; but [if so, their perception must be successive 
not coinstantaneous, for] in one and the same faculty the 
perception actualized at any single moment is necessarily one, 
only one stimulation or exertion of a single faculty being 
possible at a single instant, and in the case supposed here the 
faculty is one. It follows, therefore, that we cannot conceive 

20 the possibility of perceiving two distinct objects coinstan 
taneously with one and the same sense. 

But if it be thus impossible to perceive coinstantaneously 
two objects in the same province of sense if they are really 
/a 6>, manifestly it is still less conceivable that we should 
perceive coinstantaneously objects in two different sensory 
provinces, as White and Sweet. For it appears that when the 

1 b 6. There should be a full stop after Troiet. A new paragraph then 
begins, consequently eVei d( or TI seems required for ( . The apodosis 
is prefaced by oi>* fipn b 20, and really begun at hijXov em b 22. 


447 b 

Soul predicates numerical unity it does so in virtue of nothing 25 
else than such coinstantaneous perception [of one object, in 
one instant, by one tvepyfLa] : while it predicates specific l 
unity in virtue of [the unity of] the discriminating faculty of 
sense together with [the unity of] the mode in which this 
operates. What I mean, for example, is this ; the same sense 
no doubt discerns White and Black, [which are hence generi- 
cally one] though specifically different from one another, and 
so, too, a faculty of sense self-identical, but different from the 
former, discerns Sweet and Bitter : but while both these 
faculties differ- from one another [and each from itself] in 
their modes of discerning either of their respective contraries, 
yet in perceiving the co-ordinates in each province they .^o 
proceed in manners analogous to one another ; for instance, 
as Taste perceives Sweet, so Sight perceives White ; and as 448 a 
the latter perceives Black, so the former perceives Bitter. ; 

Again, if the stimuli of sense derived from Contraries arc 
themselves Contrary, and if Contraries cannot be conceived as 
subsisting together in the same individual subject, and if 
Contraries, e. g. Sweet and Bitter, come under one and the same 
sense-faculty, we must conclude that it is impossible to discern 5 
them coinstantancously. It is likewise clearly impossible so 
to discern such homogeneous sensiblcs as are not [indeed] 
Contrary, [but arc yet of different species]. For these are, 
[in the sphere of colour, for instance], classed some with 
White, others with Black, and so it is, likewise, in the other 
provinces of sense ; for example, of savours, some are classed 
with Sweet, and others with Bitter. Xor can one discern 
the components in compounds coinstantaneously (for 4 these 

1 For specific unity the (wrO^o-is is one and also its manner of operating 
is one. For generic, only the nurdijms is one. We must not suppose that 
Aristotle here confuses fi8os and yivo*. Cf. 449 18. 

2 Each sense proceeds in a different mode in discerning its specifically 
different objects ; <Vf po>s = trtpov rp6n< v (sc. TOV Kpivfiv) cf. b 26. So also 
two different senses proceed differently in this respect. Yet, notwith 
standing this difference of mode, there is an analogy between the procedure 
of ov/nv in perceiving white (the positive) and that of yfivis in perceiving 
sweet (also positive). Cf. 431* 21 seqq. with Torstrik s commentary. 

3 The completion of the argument begun here is found below, 448=* 
13-19, hence it seems that this latter passage should be transferred to 
follow 448* i. 

4 Ad-yoi . . . TTfVTf is parenthetic. Hiehl s punctuation is wrong. 

44 8 a DK SKNSU 

10 arc ratios of Contraries, as e.g. the Octave or the Fifth); 
unless, indeed, on condition of perceiving them as one. For 
thus, and not otherwise, the ratios of the extreme sounds are 
compounded into one ratio ; ] since we should have together 
the ratio, on the one hand, of Many to Few or of Odd to Even, 
on the other, that of Few to Many or of Even to Odd [and 
these, to be perceived together, must be unified]. 

If, then, the sensibles denominated co-ordinates though in 

indifferent provinces of sense (e.g. I call 2 Sweet and White 
co-ordinates though in different provinces) stand yet more 
aloof, and differ more, from one another than do any sensibles 
in the same province; while Sweet differs from White 15 even 
more than Black does from White, it is still less conceivable 
that one should discern them [viz. sensibles in different sensory 
provinces whether co-ordinates or not] coinstantaneously than 
sensibles which are in the same province. Therefore, if co- 
instantaneous perception of the latter be impossible, that of the 
former is a fortiori impossible. 

20 Some of the writers who treat of concords assert that the 
sounds combined in these do not reach us simultaneously, but 
only appear to do so, their real successiveness being unnoticed 
whenever the time it involves is [so small as to be] imper 
ceptible. Is this true or not ? One might perhaps, following 
this up, go so far as to say that even the current opinion that 
one sees and hears coinstantaneously is due merely to the fact 
that the intervals of time [between the really successive per 
ceptions of sight and hearing] escape observation. But this 
can scarcely be true, nor is it conceivable that any portion of 

j; time should be [absolutely] imperceptible, or that any should 
be absolutely unnoticeable ; the truth being that it is possible 4 
to perceive every instant of time. [This is so] ; because, if 
it is inconceivable that a person should, while perceiving him- 

1 The ratios involved in each of the great concords are reciprocal 
quantities which multiplied together give unity. Thus in the Octave 
\ x j = i ; in the Fourth -J x J = i ; in the Fifth 5 > 3 = i. This same 
operation combines the opposites Few x Many and Even x Odd. 

2 Adopting Ka\<i>. Biehl s reading is untranslatable, except in a very 
awkward fashion. z Vide Biehl s corrigenda. 

1 To demonstrate this directly Aristotle might have again employed 
his distinction between actuality and potentiality. But he chooses here 
the method of reditctio ad absurditm. 


self or aught else in a continuous time, be at any instant 
unaware of his own existence ; while, 1 obviously, the assump 
tion, that there is in the time-continuum a time so small as 
to be absolutely imperceptible, carries the implication that 
a person would, during such time, be unaware of his own 
existence, as well as of his seeing and perceiving ; [this 
assumption must be false]. 

Again, 2 if there is any magnitude, whether time or thing, 
absolutely imperceptible owing to its smallness, it follows that 30 
there would not be either a thing which one perceives, or a 
time in which one perceives it, unless in the sense that in some 
part of the given time he sees some part of the given thing. For 44^ b 
[let there be a line a/3, divided into two parts at y, and let this 
line represent a whole object and a corresponding whole time. 
Now,] if one sees the whole line, and perceives it during 
a time which forms one and the same continuum, only s in the 
sense that he does so in some portion of this time, let us 
suppose the part y/3, representing a time in which by sup- 5 
position he was perceiving nothing, cut off from the whole. 
Well, then, he perceives /// a certain part [viz. in the re 
mainder] of the time, or perceives a part [viz. the remainder] 
of the line, after the fashion in which one sees the whole earth 
by seeing some given part of it, or walks in a year by walking 
in some given part of the year. But [by hypothesis] in the part 
/3y he perceives nothing : therefore, in fact, he is said to 
perceive the whole object and during the whole time simply 
because he perceives [some part of the object] in some part of 
the time a/3. But 4 the same argument holds also in the case 
of ay [the remainder, regarded in its turn as a whole] ; 10 

1 a 26-30. t is to be supplied again with eWi a 28. This is Aristotle s 
first argument. The second ("30 448 12) shows that, on the given 
assumption, the perception of any whole would be impossible. 

- a 30. Omit, as Hiehl suggests, Km ft ma-davfTm before ert. If it is 
retained, with OUK before the preceding oto-^iverat, we must render and 
does not perceive, although he perceives , for ov . . . KW ft could not (as if 
it were ovde . . . ft) be translated not even perceives whether he perceives . 

3 Read with Alexander (YV. 150, 13) OVTW TO> ev TOUTOU nvi (of which 
TOH vvv TOVTU>V nvi of EM Y may be a corruption), and make apodosis begin 
with d(f)Tjpf)(r6ia h 5. 

4 Since it is not really possible in any concrete case to divide a whole 
object and the time of its perception, as we have divided the line, 
secluding, as if known, the part not perceived and the time in which no 
perception takes place. 



for it will be found [on this theory of vacant times and 
imperceptible magnitudes] that one always perceives only in 
some part of a given whole time, and perceives only some 
part of a whole magnitude, and that it is impossible to 
perceive any [really] whole [object in a really whole time ; 
a conclusion which is absurd, as it would logically annihilate 
the perception of both Objects and Time]. 

Therefore we must conclude that all magnitudes are per 
ceptible, but their actual dimensions do not present themselves 
immediately in their presentation as objects. One sees the 
sun, or a four-cubit rod at a distance, as a magnitude, but their 
exact dimensions are not given in their visual presentation : 
nay, at times an object of sight appears indivisible, but [vision, 
like other special senses, is fallible respecting common sen- 
sibles , c. g. magnitude, and] nothing that one sees is really 
T indivisible. The reason of this has been previously explained. 1 
It is clear then, from the above arguments, that no portion of 
time is imperceptible. 

But we must here return to the question proposed above for 
discussion, whether it is possible or impossible to perceive 
several objects coinstantaneously ; by coinstantaneously I 
mean perceiving the several objects in a time one and in 
divisible relatively to one another, i. e. indivisible in a sense 
consistent with its being all a continuum. 2 

1 Viz. in the passage 445 b 2-446* 20. 17 dt air in here is the atria of 
the proposition anaiTa . . . onn fWiY b 12-13. In the passage referred to 
Aristotle showed (<?) that all aiaOrjrd were directly or indirectly magnitudes 
and as such divisible in infinitum, and (b} that all magnitudes are 
perceptible either actually or potentially, i. e. are nlv6qra. This implies 
that the magnitudes of m o$f/r are not always determinate!) perceived, 
for sometimes an alaB^rov is only potentially divisible, not actually. He 
nowhere in the dc Sensu or anywhere else proves what he says, }> 14 
<JXX ov . . . But it follows from what he says that pty(6ns is one of the 
things about which cnraTwv rat men s perception misleads them. 

1 h 18 seqq. Omit ov ra> oVo/io) in !) 21 as a piece of dittography, and, 
reading with Alexander Km OVTVS rm>/ia>, transfer the clause *ai orra>r . . . 
ai M^el (which in its traditional place makes no sense, whether riro/<q> be 
referred to xpwtp as some take it, or to fjLopito \//v^^v, as others) to follow 
TTpos XXr;Xn b 20, as an explanation of the term orr/iw xp vt p rrpus nXXr/Xo. 
The text thus Incomes TO 6 apa Xeyco eV eVt *m aro/xcd xpov<*> npos JXXr/Xn. 
K n OVTWS dropo) a>s "navr\ ovn avi ()((t- No time is absolutely nrofioy for 
Aristotle, and he lacks a word to express our individual , which is what 
is here really meant by m-o/ios-. Hence the need of the explanation given 
of it. By nro^to) npbs nXXqXn (cf. npbs aura 446* 17) is meant that the time 
of discerning one of the two objects is identical with that of discerning 


First, 1 then, is it conceivable that one should perceive the 20 
different things coinstantaneously, but each with a different 
part of the Soul ? Or [must we object] that, 2 in the first place, 
to begin with the objects of one and the same sense, e. g. 
Sight, if we assume it [the Soul qua exercising Sight] to 
perceive one colour with one part, and another colour 3 with 
a different part, it will have a plurality of parts the same in 
species, [as they must be,] since the objects which it thus 
perceives fall within the same genus? 4 25 

the other: that they are discerned together in the same individual time. 
Keeping the vulgate reading, we may perhaps translate with another 
part of the soul, and not with the indivisible part, though with a part 
which is individual in the sens? that it is all continuous . But the notion 
of the old commentators that here, and in 451* 26, the nparov aurBrir^piov 
is referre-1 to is very questionable. 

1 20. Trpeoroy pe* here corresponds to el 8( drj in 449* 5, where 
Aristotle begins his own solution. The rrp<uroi/ pev of h 22 corresponds 
not to en b 29, but to ri fo of 449* 2, where the case of two different senses 
actualized through different parts of soul is taken up and dismissed. In 
b 24, after 7rXeiu>, re should be kept (against Haumkcr), as this corresponds 
to fn in b 29, where the second part of the argument against the hypothesis 
of different parts of soul energizing in simultaneous discernment through 
one sense is introduced. For ( n answering T* after an interval and with 
changed point of view cf. Eucken,r& usu particularism apud Aristotelem, 

p. 13. 

- b 22. fj (Ar ov) on is strange. / on generally answers to rt or fim n . 

3 b 24. xpw/za here merely = the object in general of each of the visual 
parts of soul assumed to operate at once. We need not suppose refer 
ence to colours of different species; XXou is not trtpnv, nor <iiXXa>, tTf pa>. 

4 b 25. See Alexander, pp. 157, 13-158, 16 (Wendland). The parts 
of soul are, by this hypothesis, so many al<r0qrf)pia of the same species, 
since each has x/>o>pi for object. Their aiVtfijrd being of the same genus 
makes the maOrjTrjpi-i to be of the same species - not genus. Hence the 
Kai y<ip. All atVdqrqptrr, as such (i. e. by the definition 424 :l 24, where even 
Rodier incorrectly construes as if he had TO npStrnv, and finds mention of 
the irp&Tov alff0f)Tt)piov) are of the same genus, but each nia-Orjr^ptov differs 
in species from each other as it has a different genus of a&rdip-a for its 
object. If two ruVdi/rqpta had the same geuus of mV^rd (or rather two 
absolutely similar genera, e. g. if each had xp/i) for object, these 
nltT0t]TT)pia would be ttdei rnvrd, as in the case suggested by the objection. 
The point of the present objection lies in this unparcimonious multipli 
cation of specifically identical parts of soul operating through each sense 
when discerning several objects together. The point of the next objection 
448* 28 en *rX. lies in the correlative multiplication of genera, and hence 
of sciences that would follow. For each of the parts of soul would 
be a faculty of sense with its own evnvria under it ; and thus under each 
of our five senses would be not one science (as Aristotle teaches), but 
as many sciences as there were genera or pairs of contraries : the absurdity 
being that these pairs would be of the same kind, only repeated for each 
of the different co-operant parts of soul. From the above it appears that 
Biehl s adoption of mvra after ei8fi b 25, connecting the latter with TrXfuo 
as dative of respect, is wrong. The Km yap 25 cannot be explained 

448 b DK SKNSl 

Should anyone |to illustrate how the Soul might have in it 
two different parts specifically identical, each directed to a set 
of aio-07/rci the same in genus with that to which the other is 
directed] urge that, as there are two eyes, so there may be 
in the Soul something analogous, [the reply is] that of the 
eyes, doubtless, some one organ is formed, and hence their 
actualization in perception is one ; but if this is so in the Soul, 
then, in so far as what is formed of both [i. e. of any two 
specifically identical parts as assumed] is one, the true perceiving 
subject also will be one, [and the contradictory of the above 
hypothesis (of different parts of Soul remaining engaged in simul 
taneous perception with one sense) is what emerges from the 
analogy] ; while if the two parts of Soul remain separate, the ana 
logy of the eyes will fail, [for of these some one is really formed]. 
Furthermore, [on the supposition of the need of different 
parts of Soul, co-operating in each sense, to discern different 
30 objects coinstantaneously]. the senses will be each at the same 
time one and many, as if we should say that they were each 
a set of diverse sciences: for neither will an activity exist 
without its proper faculty, nor without activity will there be 
sensation. 1 

449 a ]$ u t if the Soul does not, in the way suggested [i.e. with 
different parts of itself acting simultaneously], perceive in one 

without rnvra : and eiSfi and ye m have here their proper Aristotelean 
significance. Read also, with Bitterauf, eV for the irn\iv of KMY. 

1 Instead of one ai^drja-ts (e.g. ctyir) with its present variety of rWpyrtai, 
i.e. scnsioHCs, we should have, in each, many mV^o-cir, related severally, 
as so many diW/ictf, to different parts of soul. For the eW/jyciai under 
each ai<r6ri<ns would no longer run up into one &vvapis, but be held apart 
from one another, and imply each a Swapis (i. e. a faculty of perceiving 
(vavTia) to itself. This would (as Alexander says) be as absurd as having 
several sciences of the same theorem : for, since to each genus of 
wV0jTtt a single fWripii? corresponds, on this hypothesis there would be 
as many fnia-rij^H of the same kind as there were duvtifuis (faculties of 
perceiving contraries) under (or in) each aw-flipm. For the hypothesis 
being that, e.g. to see any two xpo>/zr at once, two different parts of 
soul should be employed, and this implying two faculties of colour- 
perception exactly alike in their mVdi?r<i. we should have, under each of 
the two, the contraries White X Black. This would be totally needless, 
except for the purpose of meeting the above psychological Cnropia, which 
(as Aristotle shows 449 a 5 seqq.) can be solved otherwise, consistently 
with the unity of each mo^r/my as a faculty, and of the soul itself as 
a whole. By the proposed solution the unity not only of each sensory 
faculty, and, in the sequel, of the soul itself, but also of each science 
would IDC totally abolished. 


and the same individual time sensibles of the same sense, a 
fortiori it is not thus that it perceives sensibles of different 
senses. For it is, as already stated, more conceivable that 
it should perceive a plurality of the former together in this 
way than a plurality of heterogeneous objects. 

If then, as is the fact, the Soul with one part perceives 5 
Sweet, with another, White, either that 1 which results from these 
is some one part, or else there is no such one resultant. But 
there must be such an one, inasmuch as the general faculty of 
sense-perception is one." What one object, then, does that one 
faculty [when perceiving an object, e.g., as both White and 
Sweet] perceive ? a [None] ; for assuredly no one object arises 
by composition of these [heterogeneous objects, such as White 
and Sweet]. We must conclude, therefore, that there is, as 
has been stated before, some one faculty in the soul with which 
the latter perceives all its percepts, though it perceives 4 each 10 
different genus of sensibles through a different organ. 

May we not, then, conceive this faculty which perceives 
White and Sweet to be one qua indivisible [sc. qua combining 
its different simultaneous objects] in its actualization, but 
different, when it has become divisible [sc. qua distinguishing 
its different simultaneous objects] in its actualization? 

1 a 6. TO (K rovTtov : cf. 448 b 28 TO e apfyoiv, where also the form of 
expression seems to put it beyond question that there is sowc resultant, 
the only question being whether or not this resultant is one. 

2 H 7. That the general faculty of perception is one has been already 
shown in de Aniitm, 426** 8 29 ; where too (426 b 29-427* 16) it is ex 
plained how a faculty numerically one can perceive opposites simul 
taneously without losing its numerical oneness. The difficulty is solved 
there as here by the doctrine that its numerical oneness is consistent with 
plurality in the relations in which it manifests itself. 

3 Jl 8. For what follows cf. 431* 17-431 ^ 2. The negative answer to the 
question rtW oiWVm o <Vo$- ; is all-important. If the conjoint percepts 
here too (as in the cases stated above, e.g. 448* 10) formed a fuy/in, or 
ran into one, simultaneous discernment of different objects could not be 
made out at all. But while TO y\vnv and TO AeuKoV are held together 
in the unity of TO mvdrjTiicbv navruv ( a 17), they are kept distinct in the 
object. Just as in Trpciy^nTa (objects in space) such qualities are present 
together, yet not confused or combined, so in the aia%>ia, or immediate 
impression of them (and also in the (/xii/Tno-^a, or subsequent representa 
tion), they are present together, yet discerned as different by the unity 
of the sensits communis to which they are simultaneously presented. In 
this solution of the dnopia Aristotle confines himself to the more difficult 
case (cf. 447 b 6, 22, 448* 13-19, 449 a 2-5), that of heterogeneous sensibles ; 
which being settled, that of the homogeneous follows. 

* a IO. After aXXo 5f KT\. supply aiarffavfrm, not alcrBavtaBai. 

449 a DE SENSU 

Or is what occurs in the case of the perceiving Soul con 
ceivably analogous to what holds true in that of the things 

15 themselves? For the same numerically one thing is white 
and sweet, and has many other qualities, [while its numerical 
oneness is not thereby prejudiced] if the fact is not that the 
qualities are really separable in the object from one another, 
but that the being of each quality is different [from that of 
every other]. 1 In the same way therefore we must assume 
also, in the case of the Soul, that the faculty of perception in 
general is in itself numerically one and the same, but different 
[differentiated] in its being ; different, that is to say, in genus 
as regards some 2 of its objects, in species as regards others. 
Hence too, we may conclude that one can perceive [numeri 
cally different objects] coinstantaneously with a faculty which 

20 is numerically one and the same, but not the same in its 
relationship [sc. according as the objects to which it is directed 
are not the same]. 

That every sensible object is a magnitude, and that nothing 
which it is possible to perceive is indivisible, may be thus 
shown. 3 The distance whence an object could not be seen 

1 TO fivat (in full ro dvai XfuKoi or yXv*ei) here = being in relationship , i. e. 
relationship of the objects to the faculty of perception. In a 18 Vu 
(sc. mV0/7T{Au) = relationship of the faculty of perception to that of con 
ception (according as the former perceives the different genera of atV#;ra) . 
This explains the change from ro emu a 1 8 to Aoyw a 20. It is our conceiving 
faculty that distinguishes ro ala-BrjTiKw irdvrwv in its relationships to its 
different classes of objects, in which therefore it differs Xoy&> or notione : 
it is r6 nlffSijTiKov irdvTtov that distinguishes \tvn6v and yAiw , which differ 
in their mode of manifestation to sense, in each particular experience. 
Hence Bonitz (Ind. Arist. 221* 56), is hardly right in identifying ro flvai 
and Xoyof here. 

2 For the construction of the genitive cf. 455* 21 ; supply nio-Qrjriiup here 
on the analogy of ma-dyad there, ro uitrQijrutov is said to differ yevei or dbu 
according as its alaBrffd differ yc wi or cifitt. This is remarkable. Should 
not the second trcpov be e repair ? Then rwv fj-tv . . . rwv 6c would simply 
explicate (Tfpw- the objects which are different some in genus, some in 
species: the mV^nicoi/ would be different and its objects would be different. 
This would make all clear. 

3 a 21-31. This argument is from the first ad hominem. Any one who 
believes (as Aristotle does not) in an mo-Brfrbv adutiptrov must believe that it 
can be situated in an indivisible place, i. e. in a mathematical point. For 
such a person (not, however, for Aristotle himself) the eo-^nroi/ *ai irpu>mv 
. . . odfv ( a 24), being identical, form such a place . But the alleged 
nla-BrjTov ddiaipfrov, if supposed to be set in this place, will be found to 
possess self-contradictory attributes ; e.g., if an object of vision, it will be 
at the same time visible and invisible; which is impossible. 

For Aristotle himself the npayrov KOI eo-^arov could not in reality run 


is indeterminate, but that whence it is visible is determinate. 
We may say the same of the objects of Smelling and Hearing, 
and of all sensibles not discerned by actual contact. Now, 
there is, in the interval of distance, some extreme place, the 
last from which the object is invisible, and the first from 25 
which it is visible. This place, beyond which if the object be 
one cannot perceive it, while if the object be on the hither 
side one must perceive it, is, I presume, itself necessarily in 
divisible. Therefore, if any sensible object be indivisible, such 
object, if set in the said extreme place whence impercepti- 
bility ends and perceptibility begins, will have to be both 
visible and invisible at the same time ; but this is impossible. 30 

This concludes our survey of the characteristics of the organs 
of Sense-perception and their objects, whether regarded in 
general or in relation to each organ. Of the remaining sub 
jects, we must first consider that of memory and remembering. 

into a point. Between visibility and non-visibility (so far as these depend 
on distance) there are for him an infinite number of gradations, corre 
sponding successively to successive possible removals of the object 
through consecutive points in the 7nW/7/ia or line of distance. These 
gradations towards invisibility represent so many degrees of potential 



449 b Wl<: have, in the next place, to treat of Memory and Re 
membering-, considering its nature, its cause, and the part of 
r the soul to which this experience, as well as that of Recollect 
ing, belongs. For the persons who possess a retentive memory 
are not identical with those who excel in power of recollection ; 
indeed, as a rule, slow people have a good memory, whereas 
those who are quick-witted and clever ace better at recollecting. 
We must first form a true conception of the objects of 

10 memory, a point on which mistakes are often made. Now to re 
member the future is not possible, but this is an object of opinion 
or expectation (and indeed there might be actually a science of 
expectation, like that of divination, in which some believe) ; 
nor is there memory of the present, but only sense-perception. 
For by the latter we know not the future, nor the past, but the 

15 present only. But memory relates to the past. No one would 
say that he remembers the present, when ] it is present, e. g. 
a given white object at the moment when he sees it ; nor 
would one say that he remembers an object of scientific con 
templation at the moment when he is actually contemplating 
it, and has it full before his mind ; of the former he would say 
only that he perceives it, of the latter only that he knows it. 
But when one has scientific knowledge, or perception, apart 

20 from the actualizations of the faculty concerned, he thus re 
members [that - the angles of a triangle are together equal to 
two right angles]; as to the former, that he learned it, or thought 
it out for himself, as to the latter, that he heard, or saw, it, or 
had some such sensible experience of it. For whenever one 
exercises the faculty of remembering, he must say within him 
self, I formerly heard (or otherwise perceived) this, or I 
formerly had this thought . 

1 The next clause shows that here urf not on is the true reading. 
- This is spurious. 


Memory is, therefore, neither Perception nor Conception, but 
a state ] or affection of one of these, conditioned by lapse of 25 
time. As already observed, there is no such thing as memory 
of the present while present, for the present is object only of 
perception, and the future, of expectation, but the object of 
memory is the past. All memory, therefore, implies a time 
elapsed ; consequently only those animals which perceive time 
remember, and the organ whereby they perceive time is also 
that whereby they remember. 

The subject 2 of presentation has been already considered ?,o 
in our work de Animar Without a presentation intellectual 
activity is impossible. For there is in such activity an incidental 450 a 
affection identical with one also incidental in geometrical 
demonstrations. For in the latter case, though we do not for 
the purpose of the proof make any use of the fact that the 
quantity in the triangle [for example, which we have drawn] 
is determinate, we nevertheless draw it determinate in quantity. 
So likewise when one exerts the intellect [e.g. on the subject 
of first principles], although the object may not be quantitative. 5 
one envisages it as quantitative, though he thinks it in abstrac 
tion from quantity ; while, on the other hand, if the object of 

1 His conjoined, as here, with nuOos can only have its usual Aristotelean 
meaning of a mode of Troiorr;?, a state. The definition of memory implies 
that in its genesis an maOrja-is (or im-oA^ty) has undergone something 
(ntidos) owing to lapse of time since the fWpytui. The residue of the 
m<rdt](ns (or V^O\T)\ISIS) so affected has become a (f>dvTa<rpa (or set of KU r/rre ir 
capable of yielding a ^nvrna-^a) related to the original nla-Sijais as its etVcor. 
This settled state of relationship, to be explained and defined more 
precisely in 451* 16, is what eiy here means. The qualification or 
modification effected by lapse of time in the residue of the nta-drjaiy (or 
vTT<.)\rj\l/is} and resulting in the settled state, is denoted by the combined 
words fir and ndOos. tr, of course, can, and does in a few places, 
mean having . Cf. Aristotle, Met. 1022 4-12 and io22 h 15-21, where 
this word is explained, as = (a] having , (b) didfaais KaS t/v fv J? KUKOK 

/, *nt r) taff avro 77 npos XXo. Such a eis- as that 
of pvrjuT) is described in the last words. It is a eis- *a# f)v pvrj^oviKwf 
diaiccirat riy Trpos TO. /xf^oyeura, as ( ntarr ^rj is a (ts *a$ f)v didttftrai TIV 
(niarTrjuoi iKcas rrpof ra fViaT^Ta. Honitz, Arist. Stud. \. p. 29, is mistaken 
when he makes eir and iraQos here undistinguishable. eis adds the 
notion of relativity to a past. This how a present state of mind can pick 
up a past is the real epistemological crux , and Aristotle, with his usual 
unerring insight, singles it out as what peculiarly demands explanation. 

* For apod, to eVfi see 45o a 12 note. Most translators render (fravTnaia 
imagination, but this, from the pyschologist s point of view, is liable to 

Cf. 427 b 29 seqq. 


the intellect is essentially of the class of things that are 
quantitative, but indeterminate, one envisages it as if it had 
determinate quantity, though subsequently, in thinking it, he 
abstracts from its determinatcness. Why we cannot exercise 
the intellect on any object absolutely apart from the l con 
tinuous, or apply it even to non-temporal - things unless in 
10 connexion with time, :i is another question. Now, one must 
cognize magnitude 4 and motion by means of the same faculty 
by which one cognizes 5 time [i.e. by that which is also the 
faculty of memory], and the presentation [involved in such 
cognition] is an affection of the sensns commnnis ; whence this 
follows, viz. that the cognition of these objects [magnitude, 
motion, time] is effected by the [said scnsus communis, i. e. 
the] primary faculty of perception. Accordingly, memory 
[not merely of sensible, but] even of intellectual 7 objects 
involves a presentation : hence we may conclude that it 
belongs to the faculty of intelligence 8 only incidentally, while 

1 roC is generic : it should not be struck out, as Freudenthal pro 

2 The heavenly bodies and their eternal laws, as well as the non- 
temporal (or eternal ) truths of mathematics. Cf. 22i b 3 seqq., ic>44 b 7. 

:; XP" VOS is essentially continuous, not an <J/ufyto?, despite its definition 

aS UpldfJLOS Klvi)<Jt)S KT\. 

* Cf. 232" 24 /iryedof 6 f(JT\v a-rruv avvf\s. 

5 Freudenthal s translation Grosse und Bewegung muss aber der 
vorstellen der Zeit vorstellt is, though correct in a sense, grammatically 
difficult. Besides what is the meaning of saying <x> (<wryKutoi>) xpuvov 
yvwpi^av ? Supply yvu>pid. The point of the text is to identify the 
faculty which perceives time (which has been shown to be that of 
memory) with that which supplies the (^avrt.\ff^(na for the use of po/ycn?. 
This is done by identifying both with that which perceives Ku/iju-iy in 
general- the empirical type and basis of continuity: for even time is 
dpi6p.os Kivr}o-fOK, and partakes in its continuity (dpi0fju>s here not implying 
that time itself is an arithmetical number essentially discontinuous). 
Freudenthal is astray in thinking ai Kivr^anv unintelligible except on his 
view of the construction. 

6 i) df pviinr) . . . (OTLv resumes, or sums up the result of, the protasis 
commenced at end 449 30, and thus prefaces wore a 13, which com 
mences the apodosis. 

7 Since vor^-d involve $fTo>umi, as shown 450* i-io, the memory of 
them involves and depends upon the same ^nvrda^ara. For such ^vi)^i] 
is the tts or n<i6o>- of i/oi/aiy (included under vnoX^is 449 24) when time 
has elapsed, and the tvcpytia has ceased. Though the vorjrd may be 
eternal, or at least non-temporal, the faculty which perceives time (TU 
npSn-ov alo-Brfrnufo) is that which supplies their empirical basis, and there 
fore the ground of remembering them. 

8 Far the easiest correction of the voovpevoi of all MSS. is Prof. By- 
water s (fitn)io .H fiVoi . Cf. 459* 8 oi df TOV fiinyooi /Wvou TO nuBos TOITO o 


directly and essentially it belongs to the primary faculty of 

Hence not only human beings and the beings which possess 15 
opinion or intelligence, but also certain other animals, possess 
memory. If memory were a function of [pure] intellect, it 
would not have been as it is an attribute of many of the lower 
animals, but probably, in that case, no mortal beings l would 
have had memory ; since, even as the case stands, it is not 
an attribute of them all, just because all have not the faculty 
of perceiving time. Whenever one actually remembers having 
seen or heard, or learned, something, he includes in this act (as - o 
we have already observed) the consciousness of formerly ; and 
the distinction of former and latter is a distinction in time. 

Accordingly, if asked, of which among the parts of the soul 
memory is a function, we reply : manifestly of that part to 
which presentation appertains ; and all objects capable of 
being presented [viz. cuV0;ra] are immediately and properly 
objects of memory, while those [viz. roijra] which necessarily 
involve [but only involve] presentation are objects of memory ^5 

One might ask how it is possible that though the affection 
[the presentation] alone is present, and the [related] fact 
absent, the latter that which is not present is remembered. 
[This question arises], because it is clear that we must con 
ceive that which is generated through sense-perception in the 
sentient soul, and in the part of the body- which is its seat, 
viz. that affection the state whereof we call memory to be 
some such thing as a picture. The process of movement 3 

fvv7ri>iii{.i>, where TOI" diniwoi /i Vou is used in answer to the ques 
tion raised 458 b I in reference to f j/oiymcof-. TO faavneitrBm can include 
Reason as well as reason///^. 

1 Reading 6vr)Tu>v, not ditynW as Biehl after Rassow. Memory is limited 
to beings which have the sense of time (TO mo-^mcov), none of whom 
possess pure intellect: so that if it were a purely intellectual function, 
01 dQavnrm might have it, but 01 OvrjroL (or ra 6vt]Ta} could not. 

2 It is an affection of soul and body conjointly, like all affections treated 
of in the Paw a Naturalia. The clause TO ... emu is difficult, but may be 
right. That thing, the e<r of which is p.vfjp.1, is a (fxivrnn-nu 45 i a 15, 
and itself is a fts- ) TTU&H- of an mardijais or vn-oX^is 1 449 b 25. What 
then is the niWos here the eiy of which is ^vr^rj ? We must conclude it to 
be the ^aPTaa/za (which in 45o a 10 we saw to be rrddos TTJS KOIVTJS mV$f;tta)r), 
to be described later on as fi\d>/ of its original. The word nddof here does 
not mean an affection of the particular mvOrja-is or rrroX^if, as in 449^ 25, 


[sensory stimulation] involved in the act of perception stamps 
in, as it were, a sort of impression of the percept, just as 
45 b persons do who make an impression with a seal. 1 This 
explains why, in those who are strongly moved owing to 
passion, or time of life, no mnemonic impression is formed ; 
just as no impression would be formed if the movement of the 
seal were to impinge on running water ; while there are others 
in whom, owing to the receiving surface- being frayed, as 

5 happens to [the stucco on] old [chamber] walls, or owing to 
the hardness of the receiving surface, the requisite impression 
is not implanted at all. Hence both very young and very 
old persons are defective in memory ; they are in a state of 
flux, the former because of their growth, the latter, owing to 
their decay. In like manner, also, both those who are too 

10 quick and those who are too slow have bad memories. The 
former arc too soft, 3 the latter too hard [in the texture of 
their receiving organs], so that in the case of the former the 
presented image [though imprinted] does not remain in the 
soul, while on the latter it is not imprinted at all. 

But then, if this truly describes what happens in the genesis 
of memory, [the question stated above arises :] when one 
remembers, is it this impressed affection that he remembers. 
or is it the objective thing from which this was derived ? If 
the former, it would follow that we remember nothing which 

15 is absent ; if the latter, how is it possible that, though per 
ceiving directly only the impression, we remember that absent 
thing which we do not perceive? Granted that there is in 
us something like an impression or picture, why should the 
perception of the mere impression be memory of something 
else, instead of being related to this impression alone ? For 
when one actually remembers, this impression is what he 

but an affection of the aiV^riKi} ^I X 7 ?- TO naPos is here, therefore, in 
apposition to TO yiyvopfvov fita rrjs rX. 45^ ^9> and TOIOVTOV olov fwyp. rt 
is the whole predicate after tlvm. 

1 This explanation of memory with the simile of the seal-impression is 
taken almost literally from Plato, Theaetitus, 191 D. 

2 Before ^r)x<crdui supply TO oV^o/ino; from b 5. For the above inter 
pretation of ^T]\f(T0m cf. Galen TIpoTpfnTiKos, 19 rot s roi^ovs . . . ypn(pms 

3 vypdrepoi. TO vypov, ( the moist = the elemental quality which ex 
plained softness in bodies ; just as TO rjpdv, the dry (a notion funda 
mental also in TO o-K^rjpdi/) explained hardness. 


450 b 

contemplates, and this is what he perceives. Ho\v then does 
he remember what is not present? One might as well sup 
pose it possible also to see or hear that which is not present. 
In reply, we suggest that this very thing is quite conceivable, -o 
nay, actually occurs in experience. A picture 1 painted on 
a panel is at once a picture and a likeness : that is, while one 
and the same, it is both of these, although the being of both 
is not the same, and one may contemplate it either as a picture, 
or as a likeness. Just in the same way we have to conceive 
that the mnemonic presentation within us is something which 25 
by itself is merely an object of contemplation, while, in relation 
to something else, it is also a presentation of that other thing. 
In so far as it is regarded in itself, it is only an object of 
contemplation, or a presentation ; but when considered as 
relative to something else, e. g., as its likeness, it is also - a 
mnemonic token. Hence, whenever the residual sensory 
process 3 implied by it is actualized in consciousness, if the 
soul perceives this in so far as it is something absolute, it 
appears to occur as a mere thought or presentation ; but if 
the soul perceives it qua related to something else, then, 
just as when one contemplates the painting in the picture as 
being a likeness, and without having [at the moment] seen ;o 
the actual Koriskos, contemplates it as a likeness of Koriskos, 
and in that case 4 the experience involved in this contempla- 
tion of it [as relative] is different from what one has when he 
contemplates it simply as a painted figure- [so in the case of 
memory we have the analogous difference, for], of the objects 

1 The apodosis to olov KT\. begins with OVTO> b 24. &><>> here and below 
= picture generally, not picture of animal . This use of the word is 
as early as Kmpedocles (Karst. 3721, and Herod, iv. 88. To restrict the 
meaning here to painted animals would spoil the illustration, since then 
<oi/ would be relative at once and from the first. 

2 Freudenthal thinks the Km unmeaning ; but on the contrary it is 
indispensable. The relative fyavrnvpa is as it were an (IK.WV (for this is 
only a simile), and this is also a reminder . So in 45i a 2 on etVcov, 
fj.i>Tin>)V(vfjL(i, because it is an ftVcoi/ it is a reminder . 

3 Every such fyiivTacrpn depends for its possibility on a Kivrjaiv within the 
organs, which persists as a survival or relic of the original perception. 

4 The reading of Bekker rt . . . re (450 31-451* I) a rare mode of 
conjunction might mark the parallelism between the cases. But KMY 
have TO (i> for (v rt in 45 i a i, and this has been translated. 

6 TO (v is, by a sort of Attic apposition, subdivided into the TO ptv and 
TO fie which follow. 

K 2 


in the soul, the one [the unrelated object] presents itself 
simply as a thought, but the other [the related object], just 
because, as in the painting, it is a likeness, presents itself as 
a mnemonic token. 

We can now understand why it is that sometimes, when we 
have such processes, based on some former act of perception, 
occurring in the soul, we do not know whether this really 
5 implies our having had perceptions corresponding to them, 
and we doubt whether the case is or is not one of memory. 
But occasionally it happens that [while thus doubting] we get 
a sudden idea and recollect that we heard or saw something 
formerly. This [occurrence of the sudden idea ] happens 
whenever, from contemplating a mental object as absolute, 
one changes his point of view, and regards it as relative to 
something else. 

The opposite [sc. to the case of those who at first do not 
recognize their phantasms as mnemonic] also occurs, as hap 
pened in the cases of Antipheron of Oreus and others suffering 
10 from mental derangement ; for they were accustomed to speak 
of their mere phantasms as facts of their past experience, and 
as if remembering them. This takes place whenever one 
contemplates what is not a likeness as if it were a likeness. 

Mnemonic exercises aim at preserving one s memory of 
something by repeatedly reminding him of it ; which implies 
nothing else [on the learner s part] than the frequent con 
templation of something [viz. the mnemonic , whatever it may 
be] as a likeness, and not as out of relation. 
15 As regards the question, therefore, what memory or re 
membering is, it has now been shown that it is the state of 
a presentation, related as a likeness to that of which it is 
a presentation ; and as to the question of which of the faculties 
within us memory is a function, [it has been shown] that it 
is a function of the primary faculty of sense-perception, i. e. 
of that faculty whereby we perceive time. 

45i a 


Next comes the subject of Recollection, 1 in dealing with 
which we must assume as fundamental the truths elicited 20 
above in our introductory discussions.- For recollection is not 
the recovery or acquisition :5 of memory ; since at the 
instant when 4 one at first learns [a fact of science] or experi 
ences [a particular fact of sense], he does not thereby * recover 
a memory, inasmuch as none has preceded, nor does he acquire 

1 In the first paragraph of this chapter Aristotle is occupied with 
correcting what he thinks the imperfect views of /m}^ as awn/pm 
(ii(T0T](rf(i)s, and of avdnvrjots as TO rf]v p,v^rji> avairo\tlv t expressed in the 
Philebits 34 A-H. There is no reference^ whatever to the metaphysical 
reminiscence theory of the Mcno and P/iaedo, as Thurot thinks. See 
note on 4$l b 6. 

2 TO IS irixciptipaTucois Xuyuif. In translating this, the authority of Bonitz 
(Index, 99 a 40) has been followed. The expression may, however, refer 
to the current discussions and assumptions (e.g. in the Platonic school) 
on the subject of memory. But appearances are in favour of Bonitz view 
here. Cf. especially 449 b 15-29 where the notion of memory as implying 
lapse of time is developed. On this implication too the notion of Re 
collection rests. On this point the significance of yap a 20 turns. For 

is not /nr;/^? Xf;>^if just because the establishment of the (is or 

7r$or, in which nvfip.*] consists, requires lapse of time ; while it is not 
di>u\Tj\lfis because before time has elapsed since the experience there 

is no pvTipr) to be recovered, while after time has elapsed the pvi ipr) may 
be revived by processes that are not dva/*nj<rif by re-learning or re- 
experiencing, instead of by an internal effort. 

3 That dnifj.vt]ats is not X^t? /ii^firjv is argued, with reference to 
a supposed initial moment of the pd&rjois or nndija-tf regarded as con 
tinuous processes, in a 21-25 <trav . . . ey-yiVmu [with a parenthetic hit 
(ot/r dwiX. npoyiyoi fv) at the theory of dvdXrj^is] and with reference to the 
final moment, when the pi#r/<n? or TTU^O-.? is supposed to be perfected, in 
(TI . . . iJLvrjfjLovtvu* 25-31. Next it is shown, 45i b 3 (m) to45l b 6 (tiKoXovdd) , 
that since ^vi)^ (or /n^orfi^u ) is possible without nvafju TjiTis, \f)\l/is /.u^/^v 
again fails as a definition ; for dvufunjats always implies the recovery of an 
interrupted iatr\pr\. Finally it is shown b 6-lo (ot-fif . . . d 

that even j-aXrj\//if ^vrj^s is not an adequate definition of dvd 
because one may recover i^vrj^rj by re-learning or re-experiencing (re- 
perceiving, &c.). For two reasons then, this last and that given paren 
thetically above, 451* 22 (oi>6/zm yap TTpoyryoffi ), avap.i r](n<: is not merely 
<ii>a\T}\l/is /ifr;/^r;f. But the short parenthetical argument is used with 
reference merely to the moment of the original experience (at which if 
one does not acquire ^v^v, a fortiori he does not recover it), whereas 
the argument 45i b 6-io is used with reference to the later period when 
\ivr)w has now been established. 

4 & 2i=fidOrj . . . 7r0r/, and a 23 tyyivT)Tui. We must attend to the 
meaning of the aorists, which is carefully calculated here by the writer. 


one ab initio. It is only at the instant when the aforesaid 
state l or affection [of the cuo-0?;o-ts or VTTOATJV/UV ; see 449 b 24 ) 
is implanted in the soul that memory exists, and therefore 
25 memory is not itself implanted concurrently with the con 
tinuous implantation of the [original] 2 sensory experience. 

Further: at the very individual and concluding :! instant 
when first [the sensory experience or scientific knowledge] has 
been completely implanted, there is then already 4 established 
in the person affected the [sensory] affection, or the scientific 5 
knowledge (if one ought to apply the term scientific know 
ledge to the [mnemonic | state or affection ; and indeed one 
may well remember, in the incidental sense, some of the 

1 a 23. v) (t-ts Km TO rniQo: . Here, if we should not read //, we must take *m 
= I). The mnemonic ir and irdQos here are not to be taken for the primary 
experiences referred to in n 21, a 25, where the words TOTTPCOTOI/ are used to 
mark the difference. Hut ndflos is ambiguous, referring sometimes (as 
in a 26) to the primary affection of the subject of a sensory experience, 
sometimes (as in 449 * 25 ) to the mnemonic affection which this experience 
itself undergoes by lapse of time. In a 24 it has both meanings. 

2 Therefore the disputed definitions fail with regard to the initial stage, 
not only as to recollection, but even as to memory, of which also they 
betray a misconception. 

:< Kampe s explanation (after Themistius) of TO> TO/M&> Km ea-^ara) here 
as das letzte und untheilbare Sinncsorgan is unsatisfactory. c (rx<ira> 
denotes the limit of the completion of the experience- the nndrja-tt or 
m i6t1(Tis. [\Ve agree with Kampe and Themistius (241. 29, ed. Spengel), 
and would translate : * has come to be present in the individual and 
ultimate organ. Edd.) 

4 There is no tautology, and, if there were, Freudenthal s TI before ro>, 
a 25, would not stave it off. The point of the proposition mt iyytyovt, TOT 
twndpxti n^n lies in the contrasted meaning of these two verbs : when 
once the irdffos or firtorijur) has been perfectly engendered, thereupon or 
therein the foundation of memory the immanence of the nddos or iirurriiiu\ 
is laid. The ird&os or c/rforr}/i>7 does not pass away, but abides as an 
npx i in the mind, which is the force of fVvir<i/),\-ei. But memory itself is 
not there yet : time must first elapse. 

To understand this passage we have to bear in mind Aristotle s definition 
of fjfir) as = T<J cyyus TOU irapovros vvv nro/^ioi p.tpos roO fu\\ovros \povov 
222 7. Thus fjSr) here denotes the very moment of the went referred 
to in TO) riro/Lto) KUI f<r\ur<p OT( TO irpurrnv fyytyovt, regarded as first in 
a coming scries of moments. The experience occurs in the first moment, 
and in that and all succeeding moments the ntWus or fViorr/fjij is found to 
be established, ro/uf vrrd^oj is balanced by TO fit ^.v^ovtvfiv u 2^: theiratfoj 
or cjrt<rri]pt) to which memory shall refer is now indeed implanted, but no 
time has yet passed. Before TO /ii/fj/joj^iW is possible, time must have 
passed. This irdffos is not the irdBos (or Zit) in which memory has been said 
to consist. The latter is a Trade* ^/"the ma-drja-is or vrroX^ir, i. e. a modifica 
tion in their residual Ku-qo-m caused by lapse of time. The former is the 
original sensory experience to which memory shall refer. 

fl Sc. in the person who has learned it : after ttrtari^ understand TW 


things [i.e. ra Ka66\ov] which are properly objects of scientific 1 
knowledge) ; but to remember, strictly and properly speak 
ing, 2 is an activity which will not be immanent until the 3 
original experience has undergone lapse of time. For one 
remembers now what one saw or otherwise experienced 
formerly ; the moment of the original experience and the 
moment of the memory of it are never identical. 

Again, 3 [even when time has elapsed, and one can be said 
really to have acquired memory, this is not necessarily 
recollection, for firstly] it is obviously possible, without any 45 1 b 
present act of recollection, to remember as a continued 
consequence of the original perception or other experience ; 
whereas 4 when [after an interval of obliviscence] one recovers 
some scientific knowledge which he had before, or some per 
ception, or some other experience, the state of which we above 
declared to be memory, it is then, and then only, that this 
recovery may amount to a recollection of any of the things 
aforesaid. But, [though, as observed above, remembering does 5 
not necessarily imply recollecting], recollecting always implies 

is a %is imoSdKTtKr) H39 b 31. In the sense in which it 
is spoken of as 6Wa/*fi (Met. ic8/ :i 15, cf. Locke s Habitual Know 
ledge ) it can subsist in the mnemonic <tr ; for we may remember* 
T KaOt iXov HUTU (rvupttfirjKO ;, as explained 450* 23-25. "Ei-m : some of the 
objects of e/iio-riy/iq ; for this word was (like our science ) extended to 
include even ^ TIUKTIKJ;, and many other matters of the sort that can be 
direct objects of memory. The question here raised about the term 
e7ri<jTJ/p; being used of a (is shows how far tis is from meaning a 
having in this connexion. 

2 K<it) Hiiro, i.e. as distinct from TO Kara <r. fii/., and as opposed to TO 
(vvirapx (iv iriidof r) Tt]v fTrtar^ftijv. Incidental as well as direct 
remembering involves time-lapse. 

3 Freudenthal is right in interpreting this argument as directed against 
the proposition atfupvijais = pvrju^s \f)\j/is ; for a person may have 
acquired /Apq/ii? but not parted with it, and oVo/u/qo-i? implies always at 
least an interruption of /iv^i?, though it implies more, as will be shown. 
Freudenthal wrongly thinks that Aristotle will not allow dya/^o-ii- to involve 
l*vi jp.t)s iii>d\r)\lsis at all only a recovering of the en-iorr}/^ or awQrjcris. But 
the expression fivrifajsavaX^is was part of the traditional definition: emiXa/i- 
ftavtiv nvi)wv is used by Plato, Phil. 34 B, and Aristotle has no objection 
to it as a definition, provided it be qualified by reference to the TrXeuoi/ 
apxn of b 10 below. In accepting the expression, thus qualified, he may be 
following the f iri\(ipr]^aTiKo\ Aoyoi, in the sense referred to above in the note 
on these words as alternative to that in which they are taken by Bonitz. 

4 There should not be a full stop, but only a colon, or comma, before 
u\\(i 45 i b 2. Just before, /n/^/noi/f utti/ = /ipq/joyci ofra ditnt\(ii>, which is 
contrasted here with TO ava\ap.f3dvftv r/)v f Tno-rr//^ */ ri)v (ua-dr^mf. 


remembering, 1 and actualized memory follows [ upon the 
successful act of recollecting]. 

But secondly, 2 even the assertion that recollection is the 
reinstatement in consciousness of something which was there 
before but had disappeared requires qualification. This 
assertion may be true, but it may also be false ; for the same 
person may twice learn [from some teacher], or twice discover 
[i. e. excogitate], the same fact. Accordingly, the act of re 
collecting ought [ in its definition] to be distinguished from 
these acts ; i. e. recollecting must imply in those who recollect 
the presence of some spring { over and above that from which 
they originally learn. 

TO Acts of recollection, as they occur in experience, are due 
to the fact that one movement has by nature another that 
succeeds it in regular order. 

If this order be necessary, whenever a subject experiences 
the former 4 of two movements thus connected, it will [invari 
ably] experience the latter ; if, however, the order be not 
necessary, but customary, only in the majority of cases will 
the subject experience the latter of the two movements. But 
it is a fact that there are some movements, by a single experi 
ence of which persons take the impress of custom more deeply 

15 than they do by experiencing others many times; hence r> 

1 The text is correct : TO fjLvijfjLovtvfiv is a necessary incident of TO 
ura/u/u qadat, and the latter is accompanied by and implies a reinstate 
ment of 17 pvrinr). This last is both the condition and the consequence 
of avap.vr}iris i the condition, for if there be no (potential) pv^i], nvap. is 
impossible (cf. 452* 7 ovxc n pfnvryrm) ; the consequence, for <w//zi . results 
in the reviviscence of (actual) /u/r}^. A man has not the power to 
recollect what is not in his mind, said Dr. Johnson, but when a thing is 
in his mind he may remember it. 

- Even here Plato had been beforehand with Aristotle. Cf. Phil. 34 B 
OTUV [7; ^I X }] roAc<racrn fiv^ijv . . . avdts ravrrjv avarroXfjay nti\iv nvn] cv 
fuvrfjj where both the interval of obliviscence and the internal activity 
are required for the definition of Recollection. So in the Meno 85 i> 

rraw yt. Both in Meno 81 D and PAaedo 73 n recollection is conceived 
as a tfirriais. Aristotle is superior to Plato chiefly in the detail with 
which he examines the process of <wi/ii//;o-tr. 

For the meaning of rrXfiW upxn see below, 452" 4- 7. and 452 a 11-12. 

4 Grammar and sense require eKtivrjv here. 

5 How can one reason (816) from cWow to *Wi ? Try how one will, 
one cannot, with Biehl s text, avoid logical absurdity and confusion. 
Read tvias (sc. Kivi](Tfi$) b 14, nXXay }> 15, and eYf/xi l) 16. Freudenthal in 
recommending also Kivovpfvns b 15 seems to miss seeing that the 



upon seeing some things but once we remember them better 
than others which we may have seen frequently. 

Whenever, therefore, we are recollecting, we are experi 
encing 1 certain [read ra-ds with Freudenthal] of the antecedent 
movements until finally we experience the one after which 
customarily comes that which we seek. This explains why 
we hunt up the series 2 [of Kii^o-ei?], having started in thought 
either from a present intuition or some other, and from some 
thing either similar, or contrary, to what we seek, or else from 
that which is contiguous 3 with it. Such is the empirical ground 20 
of the process of recollection ; for the mnemonic movements 
involved in these starting-points are in some cases identical, in 
others, again, simultaneous, with those of the idea we seek, while 
in others they comprise a portion of them, so that the remnant 
which one experienced after that portion [and which still 
requires to be excited in memory] is comparatively small. 

Thus, then, it is that persons seek to recollect, and thus, too, 
it is that they recollect even without the effort 4 of seeking to 

construction is Kipcirat TIS itivrjo iv nva not Kivtlmt nivrjaif. The 
TroXXa and Kivtja-ii Kivqo-iv below 452* 9, and the o-a>fuiT</cof n Kivd 453 :i 
22 stand o i a different footing ; for there the person is supposed to 
be making active voluntary efforts to stir up or arouse some idea. 
Besides, the expression m Ktvrjfrfis f6i(ovrui would be absurd : it is the 
persons that (6iovrai. 

What Aristotle is thinking of here is the greater impressiveness of 
some experiences as compared with others : he is not alluding to the 
greater impressibility of some persons as compared with others ; but the 
idea that he must also have referred to the latter point is possibly what 
first corrupted the text. The use of nvypovcvopcv, however, the first 
person standing for all persons- shows that the latter point was not 
intended here. 

1 Here Kitfovpcffa includes both the active and the passive sense. This 
twofold aspect is referred to below b 22-23 C r l ro ^ l " r(s K(li M Cirovvrts. 

2 For the meaning of TO e 0cr/r (which is not a continuum) see Phys. 
231* 22, 259* 16. 

3 i. e. as coefficient in one total idea. The association between the 
parts and the whole would be the typical form of all association. This 
fundamental law of all association of ideas might be called the law of 
totality. See Hoffding, Psych, p. 159, E. T. Such seems the force of 
the compound avvfyyvs in h 20. By TO vvv of course is meant not an 
abstract instant of time, but the concrete filling of an instant. \Ve may 
begin by calling to mind what we were thinking of at any moment, 
or start from what we are thinking of now. Thus the time-factor in 
recollection is put in the forefront here, though not fully dealt with till 
45 2b 7-453*4- 

* For such non-voluntary avapvrjvis cf. infra 453 a 17-18. The train of 
ideas is part of the mechanism of nature, which the will avails itself of, 
but which may lead to recollection without an effort of will. 


do so, viz. when the movement implied in recollection has 
25 supervened on some other which is its condition. For, as a 
rule, it is when antecedent movements of the classes here 
described have first been excited, that the particular movement 
implied in recollection follows. We need not examine a serie-s 
of which the beginning and end lie far apart, in order to see 
ho\v [by recollection] we remember l ; one in which they lie 
near one another- will serve equally well. For it is clear that 
the method is in each case the same, that is, one hunts 
up the objective series, without any previous search or previous 
recollection. For [there is, besides the natural order, viz. the 
order of the Tr/^ay/jiara, or events of the primary experience, 
also a customary order, and] by the effect of custom the 
mnemonic movements tend to succeed one another in a certain 
30 order. 3 Accordingly, therefore, when one wishes to recollect, 
this is what he will do : he will try to obtain a beginning of 
movement whose sequel shall be the movement which he 
desires to reawaken. This explains why attempts at re 
collection succeed soonest and best when they start from a 
452 a beginning [of some objective series]. For, in order of succession, 
the mnemonic movements are to one another as the objective 
facts [from which they are derived]. Accordingly, things 
arranged in a fixed order, like the successive demonstrations 
in geometry, are easy to remember [or recollect], 4 while badly r> 
arranged subjects are remembered with difficulty. 

Recollecting differs also in this respect from relcarning, 

5 that one who recollects will be able, somehow, to move, 

solely by his own effort, to the term next after the starting- 

1 All uvapvrjais if successful ends in /W^i/ actual memory. Hence it 
is idle to say that pt^adai is confused with dyaiu/btpqajcco-doi here or in 

a TU ffvvcyyvs, i.e. a train of ideas whose extremes the mnemonic dpx>i 
and l] Kwrjais fnfivT) 1 are not far apart from one another \ TU noppo) just 
above is the opposite. 

There must not have been previous (rjTqo-ts or (wi^i^o-is-, for previous 
(t jTrjais or dvdpivi](Tis would have tended to establish tti^s, and to 
prejudice, so far, our efforts to discover the natural rpinrot of (ii/a/ 
with which Aristotle is here concerned. 

4 The distinction of n^nn and avupvqa-ts cannot be preserved in et 
fiovfvra and such compounds. 

TU 0<u>Xa here = T \v&r)v of 1409* 5, TU ^irpa nuvTa fjaHjpovtvovot /yt 


point. When one cannot do this of himself, but only by 
external assistance, he no longer remembers [i. e. he has totally 
forgotten, and therefore of course cannot recollect]. It often 
happens that, though a person cannot recollect at the moment. 
yet by seeking he can do so, and discovers what he seeks. 
This he succeeds in doing by setting up many movements, 
until finally he excites one of a kind which will have for its 
sequel the fact he wishes to recollect. For remembering l I0 
[which is the condicio sine qua non of recollecting] is the 
existence, potentially, in the mind of a movement capable of 
stimulating it to the desired movement, and this, as has been 
said, in such a way that the person should be moved 
[prompted to recollection] from within himself, i. e. in conse 
quence of movements wholly contained within himself. 

But one must get hold of a starting-point. This explains 
why it is that persons are supposed to recollect sometimes 
by starting from mnemonic loci. 2 The cause is that they pass 
swiftly in thought from one point to another, e.g. from milk 5 
to white, from white to mist :: , and thence to moist, from 
which one remembers Autumn [the season of mists ], if this 
be the season he is trying to recollect. 

1 Freudenthal is quite wrong in thinking that we should read here 
t, which indeed would rather require tvtpytlv than eYcipm in 

what follows. See next note. 

2 Cf. l63 b 28 ( Honiu Ind. gives a wrong reference) naQairtp yap (v T&> 
LjLi>r]fjL<>viKa) fju wuv of TOTTOI TfQtVTts (v6vs noioi/ffiv avru p.vrjfiov(v(iv. It was 
a well-known fact, and the Simonidean mnemonic art, or art of topical 
memory, was cultivated widely long before Aristotle s time, as well as ever 
since. Cf. Xen. Symp. iv. 62 (with Schneider s note) ; Cic. de Orat. ii. 
86-88; Auct. ad Herenn. iii. 16 to end; Quintil. lust. Or. xi. 2 (de 
memoria) ; Plato, Hipp. Mai. 285, where Hippias who has TO nvrjuovutov 
boasts of his power to repeat fifty names after hearing them only once. 
Cf. also Aristotle himself de An. 427 b 19 &<rnc/j of tv mis pvijpovucois 
fiBtfjifvoi Kal ftficoXorroiotfTef, and 458^ 2O oluv of 8oKovvT(s Kara TO p.vr)p.ovtKOv 
7rapiiyyf\p.(i ri6((r6at TU jTpoftaXXopfva (where of &OKOVI>T(S may be regarded 
as giving the impression present to the sleepers minds). Why SOKOVJIV and 
fi ioTf here, words which seem to express doubt of the pretensions of the 
professors of the mnemonic art ? But on the whole it seems best not to 
adopt Sir \V. Hamilton s oV fireman , very tempting as it is; for (<) the 
instances given here are not quite arovu, and (b) Aristotle habitually 
speaks with caution and reserve, often usirg such words as suggest 
hesitation even when he cannot really be in doubt. Freudenthal suggests 
rdvuna for * WOT*, but this can hardly be ventured. 

"* niyp, for Aristotle, is naturally and distinctively white : it is the im 
mixture of this that causes the whiteness of snow and foam. See Prantl, 
Arist. de Coloribits, p. 105. The history of the word in classical usage 
from Homer onwards shows that it properly meant thick or misty air. 


It seems true in general that the middle point also among 
all things is a good mnemonic starting-point from which to 
reach any of them. For if one does not recollect before, he 
will do so when he has come to this, or, if not, nothing can help 
him ; as, e. g. if one were to have in mind the numerical l series 

20 denoted by the symbols A. B, I", A, E, C,- I, H, O. For, if he 
does not remember what he wants at E, 3 then at E he re 
members 4 ; because from E movement in either direction 
is possible, to A or to C. But, if it is not for one of these 
that he is searching, he will remember [what he is searching 
for] when he has come to f, if he is searching for H or I. 6 
But if [it is] not [for H or I that he is searching, but for one 
of the terms that remain], he will remember by going to A, 
and so in all cases [in which one starts from a middle point]. 

25 The cause of one s sometimes recollecting and sometimes not, 
though starting from the same point, is, that from the same 
starting-point a movement can be made in several directions, 
as, for instance, from l~ to I or to A. If, then, the mind has 

1 Taking the series as numerical (see Smyly, 67. A . June, 1906), the only 
alterations of MSS. readings are (a) the insertion of C after E, which is 
easy; (b] the alteration of E to C in a 22, which is also easy; and (c] the 
insertion of rov before O in a 20. 

a For the use of this as a numerical symbol /// the time of Aristotle 
there is evidence enough. The disappearance of numeral letters from 
our texts is due to the rule by which the Byzantine and even earlier copyists 
translated them into words. 

3 If the text is not here dittographic, it may mean, if E itself be not 
what he wants. 

4 When he has come to E, the middle point, he will remember O ; i.e. 
being at 5 he moves to 4, and by the proximity of these in thought 
he gets 9. In Greek arithmetic in many cases the juxtaposition of 
symbols implies addition. Thus at E (which it has to be observed he 
does not ever abandon) he has also A, and so he has O. We may bring 
the case under the rule of TO ai-vtyyvs 45 i b 18-20. What he would get if he 
moved upwards, viz. EC = 1 1, is not mentioned, as thisliesoutsidethe series. 

5 When he has come to F (still, of course, keeping hold of E) he 
similarly obtains H, i. e. 5 + 3, or else he obtains I by TO (vavriov (cf. 
45i b 19) thus: in the series 3, 5, 7, of which 5 is ro /zen-or, either taxnrov 
with TO fjL(o-ov tends to bring to mind the other fo^m-ov. For this see N. E. 
iio6 a 33 seqq. Thus it is that from F E here he gets (or may get) I. 
All the cases here given come, in fact, under two of the rules mentioned as 
governing recollection in 45i ]) 18 seqq. 

From F he may go to I by fvavTunys as just explained, to A by 
proximity in the series (TO a-vveyyvs). 


not [when starting from E] moved in an old path 1 [i.e. one 
in which it moved when first having the objective experience, 
and that, therefore, in which un- ethized tfrvo-is would have it 
again move], it tends to move to the more customary ; for 
[the mind having, by chance or otherwise, missed moving in 
the old way] Custom now 2 assumes the role of Nature/ 5 
Hence the rapidity with which we recollect what we fre 
quently 4 think about. For as regular sequence of events is 
in accordance with nature, so, too, regular sequence is ob 
served in the actualization of Kiw/rms [in consciousness], and 
here frequency tends to produce [the regularity of] ; " nature. :.o 
And since in the realm of nature occurrences G take place which 45 2 b 

1 a 27. The well-supported p} with fiiu TraXmoC- has been here adopted. 
The only change desirable would seem to be the insertion of roC before naXaiov. 
Critics have not seen how the TruXmoV may differ from the customary . 
Suppose I want to recollect the name of the Spartan who said xp*)P nT<l 
Xprjuar ai rjp, and get, as a clue, the abbreviation Aristo. I once knew 
the name well, but since then my reading habits have changed. If my 
thoughts leap along their old path (as they naturally should, with the 
question and the clue to guide them) they bring me from Aristo to 
Aristodemus . If, however, they miss the old track, they bring me to 
some name with which I am now more familiar, e.g. Aristotle . Custom 
has superseded mere (pixris. Freudenthal, however, asks Aber ist nicht 
eben TO o-up^corepoi/ ebenfalls eine Affection die man vor Alters gehabt 
hat ? This is \.\\zfons et origo erroris. 

2 a 28. fjSi, i.e. at once, upon the old path having been missed, 
custom takes the reins. 

3 a 30. There being many possible paths for the mind to move in from 
F, while that taken by it in its old, i. e. original, experience is only one, 
if it misses this old track, <f>vais alone no longer rules : <6<>s also now has 
a power of interfering, and even deciding where it shall move. Thus 
the old track and the customary are contrasted; which is quite 
intelligible, for the mind may have only moved once 5u\ (roC) TrnXmoC, i. e. 
from f to the desired goal, but often from F to other points. Therefore 
when once 6 ui/a/n/ii /jo-Ko/^yor, or o (ITM, has missed the old track, he 
loses the guidance of 0i rm (for which see45i b n) in his particular quest, 
and falls under that of c$or. 

4 Reading a TroXXnKir a 28. 

TTOICJ (pvviv. For the whole cf. A T . E. II. i. 1103*20 (with Stewart s 
notes). (j>vtrts \\zrt = organic nature ; fdos = the realm of the actualization 
of Kneads in perception, c. 

(i 452 b i. E M Y omit ^ before O/IOJ &K b 2. We should, if we followed 
these MSS., suppose Aristotle to mean that Nature as a theatre or subject 
of freaks is equally present in the sphere of Custom. This, however, is 
foreign to the whole tenor of these tracts, in which tyvcris (cf. the frequent 
7r 0i;Ke, especially in 45 i b 11) implies a power making for order and 
regularity. For rrapa Qvanv cf. 77o b 9 seqq. eon yap TO rtpas (monstrous 
birth) TU>V napa tf>v(Tii> rij TTII pa fyvviv 6 ov nacniv KT\. (which last words 
show that here too he may be thinking only of organic nature). Cf. 
;67 b 5, i255 b i seqq. For nno TI^? cf. iO27 h 12, but especially 197* 36 


arc even contrary to nature, or fortuitous, the same happens a 
fortiori in the sphere swayed by custom, since in this sphere 
natural law is not similarly established. Hence it is that 
[ from the same starting-point] the mind receives an impulse 
to move sometimes in the required direction, 1 and at other 
times otherwise, [doing the latter] particularly when some 
thing else somehow deflects the mind from the right direction 
and attracts it to itself.- This last consideration explains too 
5 how it happens that, when we want to remember a name, we 
remember one somewhat like 3 it, indeed, but blunder in 
reference to [i. e. in pronouncing] the one we intended. 

Thus, then, recollection takes place. 

But the point of capital importance is that [for the pur 
pose of recollection] one should cognize, 4 determinately or 
indeterminately, the time-relation |of that which he wishes to 
recollect]. There is, let it be taken as a fact, something 
by which one distinguishes a greater and a smaller time ; and 
it is reasonable to think that one does this in a way analogous 

seqq. TO fitv yap dnb rv\ijs triiv IITTO rnvto/xarou, ToCro 6" ov nav a /TO TI ^V 
ij /if i> yap TV\T) Kal TO OTTO ri ^rjs (<TT\V otrots Kal TO tvTV%i](Tai av virdpfifv ica i 
oXa>? 7Tpais. dto Kal di dyKT) ncpl rd TT/XIKTU dvai rrjv TI/X^V. But he goes 
on (l97^ 33^ oTav yap yewjTfii TI [V nns <^>io*i] napd (pixriv^ ToYf OVK dno 
Tv\t)S fiXXfi fj.a\\ov dirb ravTOfidrov ytyovtvai (f)ap.fv t with which cf. 289 * 26 

also. Here therefore Tvxrjs^=Tavroftarov. 

1 K(l = (Kcl(re (which Aristotle does not use). Cf. the regular OKI 1/17 for 
the KivTjffis to be recollected, iiuWfv in next line, and rVcct just below 452 b 10. 
So aXXws here virtually = XAo<r (which also Aristotle does not use), though 
it comes awkwardly before the XX&K in a different sense just following. 

* E M V give avrus for avroa-f b 4, but this would make the person s will 
perverse, which would be foreign to the matter here. It is something else 
that misleads his thoughts. For avroo* cf. Plato, Rep. 369 D. We cannot 
take aQfXKy intransitively, but might read ri0c\K# (rt). Yet Aristotle 
often leaves the indefinite subject to be supplied. [(tycXxi? without a 
subject, and iivrVxrf, are difficult. Perhaps we should read avrot and 
take d(pe\KT] intransitively. Edd.] 

3 9ra/io/zoioi . It is easy to supply ^vr^tnvtvoiuv from the preceding 
clause : there is no difficulty in the accusative, for napopoiov = Trapo/ioinc 
TI (rather than ovoun), and besides even if ovopa were supplied it could 
stand, as pvr)fwvcvfiv takes accusative even with such outer object. Cf. 
1409 5 ra p.(Tpa ndvrcs pvrjuoi (vov(Jt ^inXXoi/ ru>v %vdijv* 

4 yva>pi(iv properly = to cognize (or get into the mind) X vodv = to 
have in mind. The determinate cognition of time is explained and 
illustrated (down to b 24) by the mathematical mode of determining 
distance. Then, from b 30, the indeterminate mode of estimating it is 
considered. Knowing the time is a prime help towards recollecting the 
other circumstances of an event. The time-association is a chief 
element in the memory-idea. Aristotle s tlme-Kivrjfftts in what follows 
may perhaps, as an assumption, be compared with Lotze s local signs . 


to that in which one discerns [spatial] magnitudes. For it 10 
is not by the mind s reaching out towards them, as some say 
a visual ray from the eye does [in seeing], that one thinks l of 
large things at a distance in space (for even if they are not there, 
one may similarly think them) ; but one does so by a pro 
portionate mental movement. For there are in the mind the 
like figures and movements [i. e. like to those of objects and 
events]. Therefore, when one thinks the greater objects, 
in what will his thinking those- differ from his thinking the 
smaller? [In nothing,] because all the internal though 
smaller are as it were proportional to the external. Now. 
as we may assume within a person something proportional 15 
to the forms 3 [of distant magnitudes], so, too, we may 
doubtless assume also something else proportional to their 
distances. As, therefore, if one has [psychically] the move 
ment in AB. BE, 4 he constructs in thought [i. c. knows 
objectively] FA, since AT and FA bear equal ratios respectively 
[to AB and BE], [so G he who recollects also proceeds]. Why 
then does he construct FA rather than ZH ? Is it not because 7 

1 vofl : the vutjffis referred to here and below is of course carried on 
.by the help of 0nj>ra o7znr/. 

2 b I3 read with EMY orav TO. pfifa voy, on fte iva vod if TU AoVrco : 
ort voft being used for more usual infin. after fiioiVft. One feels that (Ktivn 
must refer as elsewhere to the real or outward things . 

:i b i5 cftcd-ip. This reminds us of the def. of aurQrjins (424 a 18) as 
ftfKTtKov T>I> iil<r0Tjro>v (I8>v (ivtv Ttjs v\T)s. The word is more general than 
o-xwaTci, including forms of events as well as of objects, stored (without 
the matter) for use in imagination and memory. 

4 vSee Figure. BE = the psychic analogue of the d&os of a real object ; AH 
= the analogue ( the <*\\n of b 16) of its nrrofTT^fin; FA = the real object; AF = 
its real distance, rrjv AB ^c. xivrjatv. All the lines are lines of movement , 
by moving in which the mind constructs real things and distances, vnflv 
is used here of the inner or representative lines (the given data), Trtnclv, 
except in b 2l, of the outer objects constructed in thought, or, in other 
words, objectively known. Possibly iro^o-m should be read for i/oj/o-ru 
in b 21. The epistemological implications of iroitiv here are interesting. 

5 Not the same as saying AF : FA : : AB : BE, for so we should not have 
Km , but o)9 17 AF irpbs rt]v FA, OVTO s f] AB Trpbs ri]v BE. The proposition = 
AF : AB : : FA : BE, as required by the reasoning. 

6 The application of the geometrical illustration (prefaced by oxnrfp ]) 9 
above) to memory is left to the reader, and the apodosis did not need to 
be expressed. 

7 Manifestly AB : BE : : AF : FA. But if AF : AB were unknown, FA 
could not be determined. We have, however (thanks to the power 
w Kpivet b 8 above) the ratio of AF : AB, viz. : I. Thus FA is determined ; 
for when the mind moves in the KiVrjo-tr AB, BE, it moves at the same time 
in that of the determinative ratio 0:1. In constructing ZH it moves similarly 
in BE, but now the concurrent determinative ratio is K : A. We know 

452 b 


as AT 1 is to AB, so is to I ? These movements therefore [sc. 

in AB, BE, and in : Ij he 
has simultaneously. But if he 
wishes to construct to thought 
ZH, he has in mind BE in like 
manner as before [when con 
structing FA], but now, instead 
of [the movements of the ratio] 
: 1, he has in mind [those of 

Z I K A ^ 1C ratl I K : A ; for K : A : : 

ZA : BA. 

When, therefore, the movement corresponding to the 
object and that corresponding to its time concur, then one 
actually remembers. If one supposes [himself to move in 
these different but concurrent ways] without really doing so, 
25 he supposes himself to remember. For one may be mistaken, 
and think that he remembers when he really does not. But it 
is not possible, conversely, that when one actually remembers 
he should not suppose himself to remember, but should re 
member unconsciously. For remembering, as we have con 
ceived it, essentially implies consciousness of itself. If. however, 
the movement corresponding to the objective fact takes place 
without that corresponding to the time, or, if the latter takes 
place without the former, one does not remember. 2 
30 The movement answering to the time is of two kinds. 
Sometimes in remembering a fact one has no determinate time- 
453 a notion of it, no such notion as that, e.g., he did something or 
other on the day before yesterday 3 ; while in other cases he has 

AH, HE, and that AH : BE : : AT : I A ; . . TA = ^B~ But : ] & ivcs 

AT in terms of AH : e.g., AT = AB.i. Hence TA = - = BE.i . Simi- 


hirly, ZH would appear in terms of BE ; e.g. as BEy. 

1 b 19 AT of the codices is right, as is I of EM V in 1( 20. [The above 
explanation of b 17-24 is, in form, due to Professor Smyly. It is the same 
in principle as that given by the translator (Greek Theories of Elementary 
Cognition, pp. 320-1 n.), but it is simpler, and requires less change in the 
letters of the MSS.J 

~ Biehl s paragraphing is here wrong, emu- . . . /jc fu"?r<u b 23-29 should 
run on with what precedes, for all this has been intended to show the impor 
tance of the time for memory and therefore for recollecting. What follows, 
on the other hand, is explanatory. 

3 The olov clause refers to ^eVpw not to ov ^eVpw. Hence there is no 
need of Freudenthal s insertion on U(VTOI nort eirnintrtv : no need as far as 

CHAPTER II r 453 a 

a determinate notion of the time. Still, even though one does 
not remember with actual determination of the time, he 
genuinely remembers, none the less. Persons are wont to say 
that they remember [something], but yet do not know when 
[it occurred, as happens] whenever they do not know deter- 
minately the exact length of time implied in the when . 

It has been already stated that those who have a good 5 
memory are not identical with those who are quick at re 
collecting. But the act of recollecting differs from that of 
remembering, not only chronologically l , but also in this, that 
many also of the other animals [as well as man] have memory* 
but, of all that we are acquainted with, none, we venture to say, 
except man, shares in the faculty of recollection. The cause 
of this is that recollection is, as it were, a mode of inference.- 10 
For he who endeavours to recollect infers that he formerly 
saw, or heard, or had some such experience, and the process 
[by which he succeeds in recollecting] is, as it were, a sort of 
investigation. But to investigate in this way belongs naturally 
to those animals alone which are also endowed with the 
faculty of deliberation ; [which proves what was said above] 
for deliberation is a form of inference. 

That the affection is corporeal, i.e. that recollection is 315 
searching for an image in a corporeal substrate, is proved 
by the fact that in some persons, when, despite the most 

sense goes ; for critically the question is on a different footing, as Biehl s 
apparatus shows. 

1 *cara roi> xpoi>i . For TO ai><i^ip.vii(TK((T0m is not only logically but 
chronologically posterior to TO pvrinovfvttv. Mi/^p/ is the presupposition of 
avap.vt)(rif. A memory must have been grounded, and one must ( potentially) 
remember, before one can recollect. Cf. 45 i b I seqq.. 452*7. 

- The <Tv\\oyi<rp6s here is an inference from effect to cause from the 
(pavTavfj-a to its origin in past experience, and the process is compared to 
the I]TT]<TIS involved in deliberation, for which cf. N. E. iii. ui2 h 20-24 
o yap ftovXfvofifvos eoi*e r)Tf ii> *ni avnXvdv TOV tlprjfjifvov rpouov uxnrtp 8in- 
ypnp.p.n . . . r/ 8e ftovXfvvis natra C ) Tr ? l$ * n T U f&X arov * v T fl ova\vo"i Trp&rov 
fivat f v TIJ y(V((Ti. Thus, in avafiinjcris, ai/aXums of the (pui mo-pa, by the help 
of associations, brings back 6 avantpvr)trie6pvos to the irpaynu. oW/u^o-ic 
proceeds analytically to account for the (pavrnap-n. The only deductive 
factor in the process is the major, that every such Qavratrpa must have 
a cause (viz. an experience ) or be capable of being accounted for. This 
starts the process of (rp-rja-tf. While /3ouXe i>o-i9 ends by finding out the way to 
act) iivdfj.i Tj(ns ends by placing the 0aWn<r/z<i in its relation to past experience. 
The av\\oyi(r^os here = the deductive inference which starts the t ) 1 ? " ? -f 
the &]Tr](Tt? itself. Syllogism, as a rendering, is hopelessly wrong. 
Reasoning would serve but inference seems best. 


strenuous application of thought, they have been unable to 
recollect, it [viz. the arajuz^/o-iy the effort at recollection] 
excites a feeling of discomfort, which, even though they 
abandon the effort at recollection, 1 persists in them none 
the less ; and especially in persons of melancholic tempera 
ment. For these are most powerfully moved by presentations. 
20 The reason why the effort of recollection is not under the 
control of their will is that, as those who throw a stone cannot 
stop it at their will when thrown, so he who tries to recollect 
and hunts [after an idea] sets up a process in a material 
part, [that] in which resides the affection. 2 Those who 
have moisture around that part which is the centre of sense- 
perception suffer most discomfort of this kind. For when 
once the moisture has been set in motion it is not easily 
25 brought to rest, until the idea which was sought for has again 
presented itself, and thus the movement has found a straight 
course. 3 For a similar reason bursts of anger or fits of terror, 
when once they have excited such motions, are not at once 
allayed, even though the angry or terrified persons [by efforts 
of will] set up counter motions, but the passions continue 
to move them on, in the same direction as at first, in opposition 
to such counter motions. The affection resembles also that in 
the case of words, tunes, or sayings, whenever one of them has 
become inveterate on the lips. People give them up and 
30 resolve to avoid them ; yet again and again they find them 
selves humming the forbidden air, or using the prohibited word. 
453 b Those whose upper parts are abnormally large, as is the 
case with dwarfs, have abnormally weak memory, as compared 
with their opposites, because of the great weight which they 

1 If dvafUiarf)<TKco 0M a 18 is co-ordinated with ro Trtipffo^Xetf, *i [OVIMT*] 
being made copulative, the subject changes from T/}I> avdfunjtnv to fYt oiy, 
;md there are other difficulties; but the sense would be in keeping with 
14 25 (ens av tWXtf// TO ^rov^^ov] and with a well-known fact, for which cf. 
Prof. James s Principles of Psychology, i. 68 1 : 4 Something we have made 
the most strenuous efforts to recall, but all in vain, will, soon after we 
have given up the attempt, saunter into the mind as innocently as if it had 
never been sent for. 

2 In which memory consists, see 449 25, 450* 10. 

3 Cf. Diog. of Apollonia, apud Theophr. de Sens. 45, Diels, Vorsokrat. 
p. 345> *"* y^P Tols dvaiufwqo KOfifVois fi]v diropiav (ivai ntpl TO orr/^os 1 , orav 8e 
fvp<i>m, &i<i(TKi$v(iu8(ii xa\ tii am)v(f)if(T0<ii rfjy \vrrns. Circular motion tended 
to continue: motion in a straight line, to cease. Cf. 26i a 27-263* 3. 


have resting upon the organ of perception, and because their 
mnemonic movements are, from the very first, not able to keep 
true to a course, but are dispersed, and because, in the effort 5 
at recollection, these movements do not easily find a direct 
onward path. Infants and very old persons have bad memories, 
owing to the amount of movement going on within them ; 
for the latter are in process of rapid decay, the former in process 
of vigorous growth ; and we may add that children, until 
considerably advanced in years, are dwarf-like in their bodily 
structure. Such then is our theory as regards memory and 
remembering their nature, and the particular organ of the 
soul by which animals remember ; also as regards recollection, i 
its formal definition, and the manner and causes of its per 

F 2 



WITH regard to sleep and waking, we must consider what 
they are ; whether they are peculiar to soul or to body, 
or common to both ; and if common, to what part of soul 
or body they appertain : further, from what cause it arises 

15 that they are attributes of animals, and whether all animals 
share in them both, or some partake of the one only, others 
of the other only, or some partake of neither and some 
of both. 

Further, in addition to these questions, we must also 
inquire what the dream is. and from what cause sleepers 
sometimes dream, and sometimes do not ; or whether the 
truth is that sleepers always dream but do not always 

20 remember (their dream) ; and if this occurs, what its ex 
planation is. 

Again, [we must inquire] whether it is possible or not to 
foresee the future (in dreams), and if it be possible, in what 
manner ; further, whether, supposing it possible, it extends only 
to things to be accomplished by the agency of Man, or to those 
also of which the cause lies in supra-human agency, and which 
result from the workings of Nature, or of Spontaneity. 

25 First, then, this much is clear, that waking and sleep 
appertain to the same part of an animal, inasmuch as they 
are opposites, and sleep is evidently a privation of waking. 
For contraries, in natural as well as in all other matters, 
are seen always to present themselves in the same subject, 
and to be affections of the same : examples are health 

30 and sickness, beauty and ugliness, strength and weakness, 
sight and blindness, hearing and deafness. This is also clear 

454 a from the following considerations. The criterion by which 

we know the waking person to be awake is identical with 
that by which we know the sleeper to be asleep ; for we 
assume that one \vho is exercising sense-perception is awake, 

CHAPTER I 454 a 

and that every one who is awake perceives either some 
external movement or else some movement in his own con 
sciousness. If waking, then, consists in nothing else than 5 
the exercise of sense-perception, the inference is clear, that 
the organ, in virtue of which animals perceive, is that by 
which they wake, when they are awake, or sleep, when they 
are asleep. 

But since l the exercise of sense-perception - does not 
belong to soul or body exclusively, then (since the subject of 
actuality is in every case identical with that of potentiality, 
and what is called sense-perception, as actuality, is a move 
ment of the soul through the body) it is clear that its ;i 
affection 4 is not an affection of soul exclusively, and that 10 
a soulless body has not the potentiality" of perception 1 . 
[Thus sleep and waking are not attributes of pure intelligence, 
on the one hand, or of inanimate bodies, on the other.] 

Now. \vhereas we have already elsewhere distinguished what 
are called the parts of the soul, and whereas the nutrient is, in 
all living bodies, capable of existing without the other parts, 
while none of the others can exist without the nutrient ; it is 
clear that 7 sleep and waking are not affections of such living 15 
things as partake only of growth and decay, e. g. not of 
plants, because these have not the faculty of sense-perception, 

1 Since waking is not peculiar to soul or body, neither is sleeping; 
for sleeping is the potentiality of waking, and if the actuality can 
not be peculiar to body or to soul, neither can the potentiality be so. 
Sleep is an affection (irn6m) which renders potential the mrr$r/rm-, whose 
actuality is waking. But instead of concluding neither is the Truflov 
peculiar to soul or body , or neither is the affection peculiar to soul, 
nor can a body without soul sleep , he winds up with the conclusion : 
4 nor is a body without soul capable of sense-perception ; which involves 
the other point ; and is really what he aims at. For to be capable of 
nio-dopcadm, without being actually ai<r6avt>nfvos, is to be asleep : to be 
incapable of it is to be incapable of sleeping as well as of waking. The 
nerve of the reasoning is contained in the parenthesis. 

- i. e. in the form of rypipyo/xm. 

* Sc. that of ai(Tdr)<Tis. 

4 Sc. twos ; see 453 b 28, 29. 

5 Cf. 454 b 1 1- 12, where also what is capable of sleeping is virtually 
identified with ro fiui/arov alaQuvt(rdm\To KUT evtpy. (iurdnvofj.(vni . 

6 Sc. cannot sleep : Sleep, the mitfor, as the parenthesis shows, is 
here regarded as dui/ri/ur, waking as tvepytm, of itiadijvis. Vide de An. 
II. i. 412* 23-26. 

7 The clauses preceding SrjXoi/ on are only the preamble, not the reason, 
of what follows. For d>r . . . on cf. 443 n 23, 24. 


whether or not this be capable of separate ] existence ; in its 
potentiality, indeed, and in its relationships, it is separable [sc. 

from TO Op7TTLKOV\. 

Likewise it is clear that [of those which either sleep 
or wake] there is no animal which is always awake or 
always asleep, but that both these affections belong [alter- 
20 natcly] to the same animals. - For if there be an animal 
not endued \\ ith sense-perception, it is impossible that this 
should either 3 sleep or wake ; since both these are affections 

1 Capable of existing separately from TO QptirriKov and the vegeta 
tive functions. With rw (lai cf. 448** 20 (note), where TW Ad-yw 
explains it. Nowhere in the world can Aristotle find TO m<rdr}Tiic6t> apart 
from TO 6ptimic6v. He cannot say that it is x^ptcrTov ^rrXtoy, or xvpiarbv 
TOTTW, or fuytfot, yet it is separate TW fivtu, i.e. in its relationship to objects. 
It is separate also r// dvri/zft. This difference may be expressed by 
saying that TO dpermKov is a 8vv(ip.ts BpcnriK.^ TO nladrjrtKuv a, Bi vafjiis nto~^Ti<^. 
rfi Bwapei therefore = * in respect of its potentiality as part of soul , or 
briefly as a faculty . 

" r. jTr nvTotf TWZ- o)an = the same animals , as in 45o a 15 (repots TWV f.= 
* different animals . 

1 The difficulty of this whole passage becomes acute here. The 
traditional translation involves a misuse of ovrc before the infinitive. The 
grammatical version would be - it cannot either sleep or wake, OUT* . . . 
ovrf explicating oi>. As the text stands this would make no sense. Inserting 
// before t x" w e could restore sense and grammar. This has been assumed 
in the translation. It is to be observed that the p(v after oo-n in a 15 
has no answering fie . But Aristotle would naturally have gone on from 
plants to the case of animals which stood on the border line. Having 
said that cpvrd (which have not the organ of sense-perception) cannot 
sleep or wake, he would naturally say that if there be any animal which 
has not perception it too cannot sleep or wake. In 7;8 b 23-779* 10 he 
considers such animals, viz. (pfrpva, which (he there says) do not sleep but 
do something like it, just like plants. In Pol. I335 b 24, too, he refers 
to these before the stage of mtrlqo-tr, before which stage cp.7toui<T0tn 8d rr)v 
u/zjSAuxrif. In another respect the received translation is wrong, for 
fl ri ton (>ov cx 1 aurQrpnv does not really = if an animal is, &c. , but 
if there be any animal having mo-dqo-t? : the former would be repre 
sented rather by ft eo-Tt fwor TO f\ov mo-Orjo-tv. Thus, too, yap a 21 first 
gets any meaning, by making it refer to ot- yap . . . fyouo-j in a 17. Then, 
however, it appears that o/zoiW . . . rat/rn a 19-21 is out of its place. If, 
however, we transfer this to a 24 after mV^TKoD \ve find the next words 
tautological. So that there is something almost certainly wrong with 
the text. I believe the insertion of /i^ to be required absolutely by the 
grammar, and critically justifiable by the consideration that it would 
have easily been lost owing to the appearance it has of contradicting 
Aristotle s well-known definition of o>oi>. At least its insertion has as 
good critical ground to stand upon as that of ^ in 449 a 3 (^1/7) aitrSnvfrm. 
The general sense of a 2i 26 (ov ynp . . . cypqyopfvai) is For while 
tL ttJiout sensation no creature can do either, ivith sensation every creature 
must do both. 

An explanation of the passage from a 19 to " 32 communicated by 
Mr. Charles Cannan seems so valuable, based as it is on minute and 

CHAPTER I 454 a 

of the activity of the primary faculty of sense-perception. 
But it is equally impossible also that either of these two affec 
tions should perpetually attach itself to the same animal, e.g. 
that some species of animal should be always asleep or always *5 
awake, without intermission ; for all organs which have a 
natural function must lose power when they work beyond the 
natural time-limit of their working period ; for instance, the 
eyes [must lose power] from [too-long continued] seeing, and 
must give it up ; and so it is with the hand and every other 
member which has a function. Now, if sense-perception is the 30 
function of a special organ, this also, if it continues perceiving 
beyond the appointed time-limit of its continuous working 
period, will lose its power, and will do its work no longer. 
Accordingly, if the waking period is determined by this fact, 
that in it sense-perception is free ; if in the case of some 454 b 
contraries one of the two must be present, while in the case of 
others this is not necessary l ; if waking is the contrary of 
sleeping, and one of these two must be present to every animal : 
it must follow that the state of sleeping is necessary. Finally, 
if such affection is Sleep, and this is a state of powerlessness 
arising from excess of waking, and excess of waking is in its 5 

scholarly analysis of the sense and grammar, that his permission to print it 
has been gladly accepted. Mr. Cannan suggests that in a 21 we should read 
nv yap fl ri ftrn (coov, or fo)oi/ (popinv), and explains a 19-32 as follows: 
But it is equally plain that there is nothing which has one of the two 
always, but both affections belong to the same parts and kinds of 
animals \animnl s^ for plants are excluded above]. For [(a) as to pan s\ 
it does not follow that, if some part of an animal has sense-perception, 
it the mere part -has the faculty either of sleeping or of waking; for 
both these affections arc incident, not to a single organ, but to the 
primary faculty of sense-perception [for example, the heart is not always 
asleep and the brain always awake (cf. Michael, p. 44. 13, Arist. 453 13), 
for in the proper sense they do not sleep or wake at all] ; nor [()*as 
to kinds], on the other hand, can either sleeping or waking attach itself 
for ever, to the exclusion of the other, to the same thing, in the sense 
that some particular kind of animal [e.g. the weasel] is always awake, 
and some other [e.g. the dormouse] is always asleep. For (on) all 
things having a natural epyoi/ become incapable in time of that tpyov ; 
therefore, that of which TO ma-Bnvtadai is an epyov will become incapable 
of TO aiVddvccrdai, and leave a blank which must be filled up with sleep, 
its contrary. 

1 Read in 45 4 b I with EMY ru>v 8 (vavriatv rvv pfv avdyKrj ddrfpov del 
7rnpeii/a, ra>f 8* 01". There are certain pairs of contraries (e. g. KaKia and 
npfrrj, cf. 1 145* 25) one of which is not always predicable of living animals ; 
while there are others of which one must be always present, and to this 
class belong sleep and waking. 


origin sometimes morbid, sometimes not, so that the power- 
Icssness or dissolution of activity will be so or not ; it is 
inevitable that every creature which wakes must also be 
capable of sleeping, since it is impossible that it should con 
tinue actualizing its powers perpetually. 

So, also, it is impossible for any animal to continue always 

10 sleeping. For sleep is an affection of the organ l of sense- 
perception a sort of tie or inhibition of function imposed on 
it, so that every creature that sleeps must needs have the 
organ of sense-perception. Now, that alone which is capable 
of sense-perception in actuality has the faculty of sense- 
perception ; but to realize this faculty, in the proper and 
unqualified sense, is impossible while one is asleep. All 
sleep, therefore, must be susceptible of awakening. Accord- 

Jj ingly. almost all other animals are clearly observed to partake 
in sleep, whether they are aquatic, aerial, or terrestrial, since 
fishes of all kinds, and molluscs, as well as all others which have 
eyes, have been seen sleeping. Hard-eyed creatures and 
insects manifestly assume the posture 2 of sleep ; but the sleep 
of all such creatures is of brief duration, so that often it might 

-o well baffle one s observation to decide whether they sleep ;i 
or not. Of testaceous animals, on the contrary, no direct 
sensible evidence is as yet forthcoming to determine whether 
they sleep, but if the above reasoning be convincing to any 
one, he who follows it will admit this 4 [viz. that they do so]. 
That, therefore, all animals sleep may be gathered from 
these considerations. For an animal is defined as such by 

- $ its possessing sense-perception : and we assert that sleep is, 
in a certain way. an inhibition of function, or, as it were, a tie, 
imposed on sense-perception, while its loosening or remission 
constitutes the being awake. But no plant can partake in 
cither of these affections, for without sense- perception there 

1 What affects the fv#v/;/, affects tlie/acu/ty, and there is no need to 
press the distinction here. 

- If we cannot see that they are asleep, we can see them couching . 
The notion of KM TI; in Kotpo/icva is important ; the allusion to it contains 
the point here. 

3 fjLT(xov(n TOV KaOfv&civ, not = KuBfvdovat. The point is that mere ob 
servation cannot decide the general question : but with the a priori 
argument (6 \f\6t\s Xo yor) it helps to convince. 

4 [Read roCro for roiVw, with By water. J. P. xxviii. 243. Ecld.J 

CHAPTER I 454 b 

is neither sleeping nor waking. But creatures which have 
sense-perception have likewise the feeling of pain and plea- 30 
sure, while those which have these have appetite as well ; but 
plants have none of these affections. A mark of this 1 is 
that the nutrient part does its own work better when 455 a 
(the animal) is asleep than when it is awake. Nutrition 
and growth are then especially promoted, a fact which 
implies that creatures do not need sense-perception to assist 
these processes. 


We must now proceed to inquire into the cause why one 
sleeps and wakes, and into the particular nature of the sense- 
perception, or sense-perceptions, if there be several, on which 
these affections depend. Since, then, some animals possess r 
all the modes of sense-perception, and some not all, not, for 
example, sight, while all possess touch and taste, except such 
animals as arc imperfectly developed, a class of which we 
have already treated in our work on the soul ; and since an 
animal when asleep is unable to exercise, in the simple sense, 
any particular 2 sensory faculty whatever, it follows that in 10 
the state called sleep the same affection must extend to all :: 
the special senses ; because, if it attaches itself to one of them 
but not to another, then an animal while asleep may perceive 
with the latter : but this is impossible. 

Now, since every sense has something peculiar, and also 
something common ; peculiar, as, e. g., seeing is to the sense 
of sight, hearing to the auditory sense, and so on with the 15 
other senses severally ; while all are accompanied by a com 
mon power, in virtue whereof a person perceives tJiat he sees 
or hears (for, assuredly, it is not by the special 4 sense of sight 
that one sees that he sees ; and it is not by mere taste, or 

1 Separableness of the nutrient from the sentient faculty. 

* Sleep is an affection of the general faculty TO aiaOrjTiKuv navrcov, 
which does not preclude such exercise of this as takes place in 

3 The text is exceedingly doubtful : cf. n 25 infra (where the conclusion 
of the matter is given) &6 ni TTCKTIV vrrdpxei rnly Cot?, and also the words 
ft yap TCO Traaas TI irttrovOfval a 27-8. 

I3ut by the general sense, (/it<t related to the special . 


sight, or both together that one discerns, and has the faculty of 
discerning, that sweet things are different from white things, 
but by a faculty connected in common with all the organs of 

20 sense : for there is one sensory function, and the controlling 
sensory faculty is one, though differing as a faculty of percep 
tion l in relation to each genus of sensibles, e. g., sound or 
colour) ; and since this [common sensory activity] subsists in 
association chiefly with the faculty of touch (for this [touch] 
can exist apart from all the other organs of sense, but none 
of them can exist apart from it a subject of which we 

25 have treated in our speculations concerning the Soul) ; it is 
therefore evident that waking and sleeping are an affection 
of this [common and controlling organ of sense-perception]. 
This explains why they belong to all animals, for touch 
[with which this common organ is chiefly connected], alone, 
| is common] to all [animals]. 

For if sleeping were caused by the special senses having 
each and all undergone some affection, it would be strange 
that these senses, for which it is neither necessary nor in 
a manner possible to realize their powers simultaneously, 

30 should necessarily all go idle and become motionless simul 
taneously. For the contrary experience, viz. that they 
should not go to rest altogether, would have been more 
reasonably anticipated. But, according to the explanation 
just given, all is quite clear regarding those also. For, when 
the sense organ which controls all the others, and to which 
all the others are tributary, has been in some way affected, 
455 b that these others should be all affected at the same time 
is inevitable, whereas, if one of the tributaries becomes power 
less, that the controlling organ should also become powerless 
need in no wise follow. 

It is indeed evident from many considerations that sleep 
docs not consist in the mere fact that the special senses do 
not function or that one docs not employ them ; and that 
it docs not consist merely in an inability to exercise the 
5 sense-perceptions ; for such is what happens in cases of 
swooning. A swoon means just such impotence of percep- 

1 TO 3 fU .u al(T0r](r(i eVf/>or. Cf. 459 :v 1 6 TO & fir 
governs roO -yeYonr. Cf. 449 a 18 (note). 


tion, and certain other cases of unconsciousness also arc of 
this nature. Moreover, persons who have the blood-vessels 
in the neck compressed become insensible. But sleep super 
venes when such incapacity of exercise has neither arisen in 
some casual organ of sense, nor from some chance cause. 
but when, as has been just stated, it has its seat in the I0 
primary organ with which one perceives objects in general. 1 
For when this has become powerless all the other sensory 
organs also must lack power to perceive ; but when one of 
them has become powerless, it is not necessary for this also 
to lose its power. 

We must next state the cause to which it is due. and 
its quality as an affection. Now, since there are several 
types of cause (for we assign equally the final , the efficient . *5 
the material , and the formal as causes), in the first place, 
then, as we assert that Nature operates for the sake of an 
end, and that this end is a. good 2 ; and that to every creature 
which is endowed by nature with the power to move, but 
cannot with pleasure :i to itself move always and continuously, 
rest is necessary and beneficial ; and since, taught by cxperi- -o 
ence. men apply to sleep this metaphorical 4 term, calling 
it a rest [from the strain of movement implied in sense- 
perception] : we conclude that its end is the conservation of 
animals. But the waking state is for an animal its highest 
end, since the exercise of sense-perception or of thought is the 
highest end for all beings to which either of these appertains ; 
inasmuch as these are best, and the highest end is what is 
best : whence it follows that sleep belongs of necessity to 2 5 
each animal. I use the term necessity in its conditional 
sense, meaning that if an animal is to exist and have its own 
proper nature, it must have certain endowments ; and, if these 

1 See 449 tt 7 r " nlvBtyrinov 

2 avannvo-is is an end, i.e. a good ; but fhe end, i. e. the highest end, of 
animal life is TO nla-6. Km TO </>/)or?It>, to which VTTVOS is subordinated. Cf. 
infra a 23-25. The i\ya6<. n> TI is distinguished from TO rtXos. 

3 Anaxagoras held that all nio-d^ms is pcra himrjs. Theophr. de Sens. 
29. Cf. also Aristotle, A r . E. II$4 b 7 nei ynp novel TO ((Ooi> axrrrfp Km m 
<pv(Tio\oyoi p.ainvpni 0-i, T<> opav, TO (\Kovfiv (JH KTKOITCS elvai \vrrrjpnv. 

4 The metaphor is plain enough in the Greek word tiviinavais. 
No word in English seems to meet the case so well as rest . EM give 
KciTixpnpni . which, however, it would be difficult to translate here. But cf. 

K(lT(lfj)(fKT(li. 456 24. 


arc to belong to it, certain others likewise must belong to it 
[as their condition]. 

The next question to be discussed is that of the kind of 
movement or action, taking place within their bodies, from 
;,o which the affection of waking or sleeping arises in animals. 
Now, we must assume that the causes of this affection in all 
other animals are identical with, or analogous to, those which 
operate in sanguineous animals ; and that the causes operat 
ing in sanguineous animals generally are identical with those 
operating in man. Hence we must consider the entire sub 
ject in the light of these instances [afforded by sanguineous 
456 a animals, especially man]. Now, it has been definitely settled 
already in another work that sense-perception in animals 
originates in the same part of the organism in which move 
ment originates. This locus of origination is one of three 
determinate loci. viz. that which lies midway between the 
head and the abdomen. This in sanguineous animals is 
the region of the heart ; for all sanguineous animals have 

5 a heart ; and from this it is that both motion and the con 
trolling sense-perception originate. Now, as regards move 
ment, it is obvious that that of breathing and of the cooling 
process generally takes its rise there ; and it is with a view to 
the conservation of the [due amount of] heat in this part that 
nature has formed as she has both the animals which respire, 
and those which cool themselves by moisture. Of this 

10 [cooling process] per sc we shall treat hereafter. In bloodless 
animals, and insects, and such as do not respire, the con 
natural spirit l is seen alternately puffed up and subsiding 
in the part which is in them analogous [to the region of the 
heart in sanguineous animals]. This is clearly observable 
in the holoptcra [insects with undivided wings] as wasps and 
bees ; also in flies and such creatures. And since to move 

15 anything, or do anything, is impossible without strength, and 
holding the breath produces strength in creatures which 
inhale, the holding of that breath 2 which comes from without, 

1 TO (Tvp.<pvrov TTi tvpa, \. c. the ni vfji(i which is naturally inherent, as 
opposed to that inhaled (TO QvpaQfv (TTCIO-CIKTOV). 

a 17 ffupafov is short for / ToG 0vpa6fv trvtvparos Ka&if, as r) <rvp.(pvTos 

alSO = f] TOV (TVfl(f)VTOV 


but, in creatures which do not respire, of that which is con 
natural (which explains why winged insects of the class 
holoptera, when they move, are perceived to make a hum 
ming noise, due to the friction of the connatural spirit collid 
ing with the diaphragm) ; and since movement 1 is, in every 20 
animal, attended 2 with some sense-perception, either internal 
or external 3 , in the primary organ of sense, [we conclude] 
accordingly that if sleeping and waking are affections of this 
organ, the place in which, or the organ in which, sleep and 
waking originate, is self-evident [being that in which move- 25 
ment and sense-perception originate, viz. the heart]. 

Some persons move in their sleep, and perform many acts 
like waking acts, but not without a phantasm or an exercise 
of sense-perception ; for a dream is in a certain way a sense- 
impression. But of them we have to speak later on. Why 
it is that persons when aroused remember their dreams, but 
do not remember these acts which are like waking acts, has 
been already explained in the work Of Problems . 


The point for consideration next in order to the preceding ?o 
is : What are the processes in which the affection of waking 
and sleeping originates, and whence do they arise? Now, 
since it is when it has sense-perception that an animal must 
first take 4 food and receive growth, and in all cases food in its 
ultimate form is, in sanguineous animals, the natural sub- 35 
stance blood, or, in bloodless animals, that which is analogous 
to this ; and since the veins are the place of the blood, while 45 b 
the origin of these is the heart an assertion which is proved 
by anatomy it is manifest that, when the external nutriment 

Aristotle does not mean that whenever one 
has an mo-^o-i? he moves (or is moved) locally. The Kivelrm here and 
the mvcw a 15 refer to local movement, involving output of bodily energy, 
not to the KiVf/ai? (or stimulation) of sense. 

2 U 20 If instead of ytvopcvijg ( a 2o) yevopfvys were read, the movement 
should be regarded as prompted by the perception -- a very important 

3 oiKfias 17 aXXorpins : arising either from an intra-organic or an extra- 
organic stimulus. 

4 i.e. qua animal; before this, in the embryonic stage, it grows and is 
nourished like a vegetable. 


enters the parts fitted for its reception, the evaporation arising 
from it enters into the veins, and there, undergoing a change, 

5 is converted into blood, and makes its way to their source 
[the heart]. We have treated of all this when discussing 
the subject of nutrition, but must here recapitulate what was 
there said, in order that we may obtain a scientific view of the 
beginnings of the process, and come to know what exactly 
happens to the primary organ of sense-perception to account 
for the occurrence of waking and sleep. For sleep, as has 

10 been shown, is not any given impotence of the perceptive 
faculty ; for unconsciousness, a certain form of asphyxia, and 
swooning, all produce such impotence. Moreover it is an estab 
lished fact that some persons in a profound trance have still had 
the imaginative faculty in play. This last point, indeed, gives 
rise to a difficulty ; for if it is conceivable that one who had 
swooned should in this state fall asleep, the phantasm also which 
then presented itself to his mind might be regarded as a dream. 

15 Persons, too, who have fallen into a deep trance, and have 
come to be regarded as dead, say many things while in 
this condition. The same view, however, is to be taken of 
all these cases, [i. e. that they arc not cases of sleeping or 

As we observed above, sleep is not co-extensive with any and 
every impotence of the perceptive faculty, but this affection is 
one which arises from the evaporation attendant upon the 

20 process of nutrition. The matter evaporated must be driven 
onwards to a certain point, then turn back, and change its 
current to and fro, like a tide-race in a narrow strait. Now, 
in every animal the hot naturally tends to move [and carry 
other things] upwards, but when it has reached the parts above, 
[becoming cool, see 457 30] it turns back again, and moves 
downwards in a mass. This explains why fits of drowsiness are 
especially apt to come on after meals ; for the matter, both the 

25 liquid and the corporeal, which is borne upwards in a mass, is 
then of considerable quantity. When, therefore, this comes to 
a stand it weighs a person down and causes him to nod, but 
when it has actually sunk downwards, and by its return has re 
pulsed the hot, sleep comes on, and the animal so affected is 
presently asleep. A confirmation of this appears from consider- 


ing the things which induce sleep ; they all, whether potable ?|0 
or edible, for instance poppy, mandragora, wine, darnel, produce 
a heaviness in the head ; and persons borne down [by sleepi 
ness] and nodding [drowsily] all seem affected in this way, 
i. e. they are unable to lift up the head or the eye-lids. And 
it is after meals especially that sleep comes on like this, for 
the evaporation from the foods eaten is then copious. It also 
follows certain forms of fatigue ; for fatigue operates as a 
solvent, and the dissolved matter acts, if not cold, like food 35 
prior to digestion. Moreover, some kinds of illness have 457 a 
this same effect ; those arising from moist and hot secretions, 
as happens with fever-patients and in cases of lethargy. 1 
Extreme youth also has this effect ; infants, for example, 
sleep a great deal, because of the food being all borne upwards 
a mark whereof appears in the disproportionately large size =, 
of the upper parts compared with the lower during infancy, 
which is due to the fact that growth predominates in the 
direction of the former. Hence also they are subject to 
epileptic 2 seizures ; for sleep is like epilepsy, and, in a sense, 
actually is a seizure of this sort. Accordingly, the beginning 10 
of this malady takes place with many during sleep, and their 
subsequent habitual seizures occur in sleep, not in waking 
hours. For when the spirit [evaporation] moves upwards in 
a volume, on its return downwards it distends the veins, and 
forcibly compresses the passage through which respiration is 
effected. This explains why wines are not good for infants 
or for wet nurses (for it makes no difference, doubtless, 15 
whether the infants themselves, or their nurses, drink them), 
but such persons should drink them [if at all] diluted with 
water and in small quantity. For wine is spirituous, and of all 
wines the dark more so than any other. The upper parts, 
in infants, are so filled with nutriment that within five months 
[after birth] they do not even turn the neck [sc. to raise the 
head] ; for in them, as in persons deeply intoxicated, there is 
ever a large quantity of moisture ascending. It is reasonable, 20 

1 If V be right, \rjdapyos may be either a substantive or an adjective 
in agreement with Trvpero is understood. 

2 Not merely childish fits and convulsions, but epileptic fits. The 
word in this sense is as old as Hippocrates, and the facts here stated are 
all medical truths. 


too, to think that this affection is the cause of the embryo s 
remaining at rest in the womb at first. Also, as a general rule, 
persons whose veins are inconspicuous, as well as those who 
are dwarf-like, or have abnormally large heads, are addicted 
to sleep. For in the former the veins are narrow, so that 
it is not easy for the moisture to flow down through them ; 
while in the case of dwarfs and those whose heads are ab- 
->5 normally large, the impetus of the evaporation upwards is 
excessive. Those [on the contrary] whose veins arc large 
are, thanks to the easy flow through the veins, not addicted 
to sleep, unless, indeed, they labour under some other affec 
tion which counteracts [this easy flow]. Nor are the atra 
bilious addicted to sleep, for in them the inward region is 
cooled so that the quantity of evaporation in their case is not 
great. For this reason they have large appetites, though 
?,o spare and lean ; for their bodily condition is as if they 
derived no benefit from what they eat. The dark bile, too, 
being itself naturally cold, cools also the nutrient tract, and 
the other parts wheresover such secretion [bile] is potentially 
present [i. e. tends to be formed]. 

457 b Hence it is plain from what has been said that sleep is 
a sort of concentration, or natural recoil, 1 of the hot matter 
inwards [towards its centre], due to the cause above men 
tioned. Hence restless movement is a marked feature in the 
case of a person when drowsy. But where it [the heat in the 
upper and outer parts] begins to fail, he grows cool, and 
owing to this cooling process his eye-lids droop. Accord- 
5 ingly [in sleep] the upper and outward parts are cool, but 

1 \Vhat is meant is otherwise expressed, 458" 10 awfw pkvr] KT\. 
nvTinfpiffTaais is not here used in its strict sense, in which it involves real 
circulation . Hence ns goes with it as well as with (rvvodos. avrnrfpicrTa- 
<ri* is defined by Simplicius as a circular process in which when a body- 
is pushed out of its place that which has expelled it occupies the place, 
while that which has been thrust out pushes the adjoining body from its 
place, until the last moved in this series finds itself in the place of the 
first, which extruded something else . It depends on the fact that there 
is no vacuum. (Cf. 266" 25 seqq., 459 b 2, 472* 17 ; Zeller, Plato (E.T.), 
p. 430; Zeller, Arist. i. 515, ii. 378, n.) So Aristotle explained physical 
facts like the motion of projectiles. Plato, Tim. 79 B-E, uses the word 
TTf piwOeiv for what A. refers to avTurepiffTaais. We see the effect of the 
process when on suddenly opening a door in a room the opposite door 
shuts, or vice versa. Reference to this explains rrjs "px?is 454 h 2, q.i 1 . 


the inward and lower, i. e. the parts at the feet and in the 
interior of the body, are hot. 

Yet one might found a difficulty on the facts that sleep is 
most oppressive in its onset after meals, and that wine, and 
other such things, though they possess heating properties, arc 
productive of sleep, 1 for it is not probable that sleep should be 
a process of cooling while the things that cause sleeping arc 10 
themselves hot. Is the explanation of this, then, to be found 
in the fact that, as the stomach when empty is hot, while 
replenishment cools it by the movement it occasions, so the 
passages and tracts in the head are cooled as the : evapora 
tion ascends thither ? Or, as those who have hot water 
poured on them feel a sudden shiver of cold, just so in the 15 
case before us. may it be that, when the hot substance ascends, 
the cold rallying to meet it cools [the aforesaid parts], deprives 
their native heat of all its power, and compels it to retire ? 
Moreover, when much food is taken, which [i. c. the nutrient 
evaporation from which] the hot substance carries upwards, 
this latter, like a fire when fresh logs are laid upon it, is itself 
cooled, until the food has been digested. 

For, as has been observed elsewhere, 2 sleep comes on when ->o 
the corporeal element [in the evaporation ] is conveyed 
upwards by the hot, along the veins, to the head. But when 
that which has been thus carried up can no longer ascend, 
but is too great in quantity :! [to do so], it forces the hot 
back again and flows downwards. Hence it is that men sink 
down [as they do in sleep] when the heat which tends to keep 
them erect (man alone, among animals, being naturally erect) >$ 
is withdrawn ; and this, when it befalls 4 them, causes uncon 
sciousness, and afterwards 5 phantasy. 

Or are the solutions thus proposed barely conceivable 
accounts of the refrigeration which takes place, while, as 

1 9. There should be only a comma after TOHIVT<I. <V here gives the 
argument from the opponent s point of view, and = for . 

2 De Part. An. ii. 7, 653* 10. 

3 A new factor mechanical pressure is here introduced. 

4 ffrtirctroy sc. TO vire <nrd(rda i TO Btpfu w. Bonitz, Ind. 267 a 32 makes 
TO Qfppm alone agree with eVtTTfo-oV, and so Freudenthal translates * wieder- 
eindringend efzeugt das Warme Bewusstlosigkeit . fmmnrfiv expresses 
a hostile attack, an onset. 

Afterwards , i.e. when the process of SIUK/UO-IS sets in ; cf. 46i a 25. 



a matter of fact, the region of the brain is, as stated else 
where, the main determinant of the matter ? For the brain, 
30 or in creatures without a brain that which corresponds to it, 
is of all parts of the body the coolest. Therefore, as moisture 
turned into vapour by the sun s heat is, when it has ascended 
to the upper regions, cooled by the coldness of the latter, and 
becoming condensed, is carried downwards, and turned into 

458 a water once more ; just so the excrementitious evaporation, when 

carried up by the heat to the region of the brain, is condensed 
into a phlegm (which explains why catarrhs are seen to 
proceed from the head); while that evaporation which is 
5 nutrient and not unwholesome, becoming condensed, descends 
and cools the hot. The tenuity or narrowness of the veins 
about the brain itself contributes to its being kept cool, and 
to its not readily admitting the evaporation. This, then, is 
a sufficient explanation of the cooling which takes place, 
despite the fact that the evaporation is exceedingly hot. 

10 A person awakes from sleep when digestion is completed: 
when the heat, which had been previously forced together in 
large quantity within a small compass from out the surround 
ing part, has once more prevailed, and when a separation has 
been effected l between the more corporeal and the purer 
blood. 2 The finest and purest blood is that contained in the 
head, while the thickest and most turbid is that in the lower 

15 parts. The source of all the blood is, as has been stated 
both here and elsewhere, the heart. Now of the chambers in 
the heart the central communicates with each of the two 
others. Each of the latter again acts as receiver from each, 
respectively, of the two vessels, 3 called the great and the 
aorta . It is in the central chamber that the [above-men- 

20 tioned] separation takes place. To go into these matters 
in detail would, however, be more properly the business of 
a different treatise from the present. Owing to the fact that 
the blood formed after the assimilation of food is especially 

1 Sc. in the heart ; see below a 19. 

2 Contained in the * evaporated substance now collected back into the 

3 To use the term artery here in translation would mislead any mere 
Knglish reader into thinking that Aristotle knew the difference between 
arteries and veins. 


in need of separation, sleep [then especially] occurs [and 
lasts] until the purest part of this blood has been separated 
off into the upper parts of the body, and the most turbid 
into the lower parts. When this has taken place animals 
awake from sleep, being released from the heaviness conse 
quent on taking food. 

We have now stated the cause l of sleeping, viz., that it 25 
consists in the recoil by 2 the corporeal element, upborne by 
the connatural heat, in a mass upon the primary sense-organ ; 
we have also stated ivhat 3 sleep is, having shown that it is 
a seizure of the primary sense-organ, rendering it unable to 
actualize its powers ; arising of necessity (for it is impossible 30 
for an animal to exist if the conditions which render it an 
animal be not fulfilled), i. e., for the sake of its conservation 4 ; 
since remission of movement tends to the conservation of 

1 This gives the cause o6tv 17 *u;<m-, or efficient cause : the kinetic 
energy of TO Btppnv. The material cause is TO vu6vp.iu>p.(vov, and the other 
material conditions, regarded statically, i.e. in abstraction from their 

2 17 ... avTiirfpitrraiTis sc. yiyvopfinj. In 45& 1 I TO Btpp tv is used for 
TO (T<t)p.aTo)d(s TO dva(f). VTTO TUV <TVH<PVTOV 6tpn<>v here. The agency which 
causes the recoil is the cold of the brain : hence wro a 26 ^ (not caused 
by , but) undergone by . The VTTO in this sense is curious, but oV<- 
7re/)i <rnirrif (corresponding to dvTHTtptffTrjvnt, not to avrnrtpmrrttvai} is a sort 
of manoeuvre effected by the substance. 

3 i. e. its definition or formal cause. 

4 cra>TT]pia. is theyftw/ cause. 

n]7 S OMNI IS 

WK must, in the next place, investigate the subject of the 
dream, and first inquire to which of the faculties of the soul it 
presents itself, i. e. whether the affection is one which per 
tains to the faculty of intelligence or to that of sense- percep 
tion ; for these are the only faculties within us by which we 
acquire knowledge. 

If, then, the exercise of the faculty of sight is actual seeing, 
that of the auditory faculty, hearing, and, in general that of 
the faculty of sense-perception, perceiving ; and if there are 
5 some perceptions common to the senses, such as figure, mag 
nitude, motion, &c., while there are others, as colour, sound, 
taste, peculiar [each to its own sense] ; and further, if all 
creatures, when the eyes are closed in sleep, are unable to see, 
and the analogous statement is true of the other senses, so 
that manifestly we perceive nothing ! when asleep ; we may 
conclude that it is not by sense-perception we perceive 
a dream. 

But neither is it by opinion that we do so. For [in 
10 dreams] we not only assert, e.g., that some object approach 
ing is a man or a horse [which would be an exercise of 
opinion], but that the object is white or beautiful, points 
on which opinion without sense-perception asserts nothing 

1 458 b 8. Read after Christ s conj. ov8ti> eV. We do not perceive any 
thing in sleep with \\\& particular or special senses, but the npwov al<r6rrn.Kfo 
is active in the dream, i. e. we perceive, in a way to be explained 
in these chapters, with the general sense as re-presentative faculty. 
Biehl wrongly marks the apodosis at cotrre b 8: it really begins at OVK 
apa ye b 9. The coore clause states the consequence of the fact contained 
in the clause commencing aSvmrcl 8, and therefore belongs to the 
premisses. We cannot by sense perceive either the KOIVU or the 1dm 
in sleep, so that we cannot then perceive anything at all ; therefore it 
is not by sense that we perceive a dream (not, that is. by special sense, 
as afterwards to be explained). Such is the argument. 

CHAPTER T 458 b 

either truly or falsely. It is, however, a fact that the soul 
makes such assertions in sleep. We seem to see equally well 
that the approaching figure is a man, and that it is white. 
[In dreams], too, we think something else, over and above 15 
the dream presentation, just as we do in waking moments 
when we perceive something ; for we often also reason about 
that which we perceive. So, too, in sleep we sometimes have 
thoughts other than the mere phantasms immediately before 
our minds. This would be manifest to any one who should 
attend and try, immediately on arising from sleep, to remem 
ber [his dreaming experiences]. There are cases of persons 20 
who have seen such dreams, those, for example, who believe 
themselves to be mentally arranging a given list of subjects 
according to the mnemonic rule. They frequently find 
themselves engaged in something else besides the dream, viz. 
in setting a phantasm which they envisage into its mnemonic 
position. 1 Hence it is plain that not every phantasm in sleep 
is a mere dream-image, and that the further thinking which we 25 
perform then is due to an exercise of the faculty of opinion. 

So much at least is plain on all these points, viz. that 
the faculty by which, in waking hours, we are subject to 
illusion when affected by disease, is identical with that which 
produces illusory effects in sleep. So, even when persons are 
in excellent health, and know the facts of the case perfectly 
well, the sun, nevertheless, appears - to them to be only a 
foot wide. Now, whether the presentative faculty of the 
soul be identical with, or different from, the faculty of sense- 3 
perception, in either case the illusion does not occur without 
our actually seeing or [otherwise] perceiving something. Even 

1 The word faiivaa pa here and in b 24 is, according to Freudenthal, a 
generalized vorstellung , of the nature of a concept. But as \ve see from 
458 b 1 8 and 462* 29 its proper application is to the dream-image. Here 
that which is napa TO c vwv s not the mere ^uiyrrur/ui, but the activity 
of thought expressed in riBeadm ds rbv ronov <j)(ii>Ta<rp.a, this clause being 
in apposition to <7A\o TJ, which it explains. In h 24, however, $u*>ruo>ui 
seems to refer to that activity. 

2 5oK6t is here used improperly for the more correct JHIIV(T<U. See 
tie An. 428 b 1-3 (/xitWrm p.iv o r/Ato? Tro&mov, TrenfHTTin o eiVm [idfa TTJS 
oiKovfjLfvrjf. See also 46o b 18. We cannot suppose Aristotle to be here 
alluding to the unscientific opinion of those who (like Epicurus and his 
school afterwards) insisted that the sun is only so large as it seems to 
the eye. Cf. Kant s reference to the persistent illusion of sense on 
this point (of the size of the sun or moon). 


to see wrongly or to hear wrongly can happen only to one 
who sees or hears something real, though not exactly what he 
supposes. But we have assumed that in sleep one neither 
459 a sees, nor hears, nor exercises any sense whatever. Perhaps 
we may regard it as true that the dreamer sees nothing, yet 
as false that his faculty of sense-perception is unaffected, the 
fact being that the sense of seeing and the other senses may 
possibly be then in a certain way affected, while each of these 
affections, as duly as when he is awake, gives its impulse in 
5 a certain manner to his [primary] faculty of sense, though 
not in precisely the same manner 1 as when he is aw r ake. 
Sometimes, too, opinion says [to dreamers] just as to those 
who are awake, that the object seen is an illusion ; at other 
times it is inhibited, and becomes a mere follower of the 

It is plain therefore that this affection, which we name 
dreaming , is no mere exercise of opinion or intelligence, 

10 but yet is not an affection of the faculty of perception in the 
simple sense. 2 If it were the latter it would be possible 
[when asleep] to hear and see in the simple sense. 

How then, and in what manner, it takes place, is what we 
have to examine. Let us assume, what is indeed clear 
enough, that the affection [of dreaming] pertains to sense- 
perception as surely as sleep itself does. For sleep does not 
pertain to one organ in animals and dreaming to another ; 
both pertain to the same organ. 

15 But since we have, in our work on the Soul, treated of 
presentation. 4 and the faculty of presentation is identical 

1 ov\ . . . QHTTffi) : not directly from the mV$//T5i>, but indirectly or me 
diately from the residual KIISTJO-IS the ina-di^a vn-oXotn-oi/. 

2 aw0avt(r0ai TT\COV : opp. Kara 7r/>oo-$f(rij , with a difference or qualifi 
cation. Dreaming is afterwards shown to be alcrdavfa-dai in a secondary 
sense, or Kara (rvupcftriKtis, i. e. in virtue of the residual m^o-tiv left in the 
organs after mo-Br^ris has departed. 

s 42; b 27-429 a 9. 

4 The word * imagination , owing to popular and psychological asso 
ciations, is unfitted to be a rendering of 0a*ru<ria here, and presenta 
tion is now a recognized term x re-presentation. For the operation 
of fydvrav m in ordinary aiaQijffts see 460 18, where ^aiverm to have a 
presentation a 0Jrrao-/Li not a representation. Presentation differs 
from (iio-dr)<ris (in which it is involved). It is the aspect in which that 
which mcrdfycrif apprehends is put before the mind s eye, so to speak. 
- takes the tifiq fivtv vX^ of mVtfr/ra, and presents them as 

CHAPTER I 459 a 

with l that of sense-perception, though the essential notion of 
a faculty of presentation is different from that of a faculty 
of sense-perception ; and since presentation is the movement 
set up by a sensory faculty when actually discharging its 
function, while a dream appears to be a presentation (for 
a presentation which occurs in sleep whether simply 2 or in 20 
some particular way is what we call a dream): it manifestly 
follows that dreaming is an activity of the faculty of sense- 
perception, but belongs to this faculty qua presentative. 


We can best obtain a scientific view of the nature of the 
dream and the manner in which it originates by regarding it 
in the light of the circumstances attending sleep. The objects 25 
of sense-perception corresponding to each sensory organ pro 
duce sense-perception in us, and the affection due to their 
operation is present in the organs of sense not only when 
the perceptions are actualized, but even when they have 

What happens in these cases may be compared with what 
happens in the case of projectiles moving in space. Eor in 
the case of these the movement continues even when that 
which set up the movement is no longer in contact [with the 30 
things that are moved]. For that which set them in motion 
moves 15 a certain portion of air, and this, in turn, being moved 
excites motion in another portion ; and so, accordingly, it is 
in this way that [the bodies], whether in air or in liquids, 
continue moving, until they 4 come to a standstill. 

material of thought or opinion. This explains how TO cu/m (JHIVTIHTTIKU (the 
essential notion of a faculty of presentation) differs from ri ftrnt mo-drjTiKu. 
See 449* 16-20, 454* 19, 455* 21, with notes. 

1 i. e. inseparable numero, and in concrete existence, from it. 

2 U7r\a>f : without specifying particular conditions: rpunov rif.i, i.e. in 
the way defined 462* 29, where the $uvra<r/ia of the dream is said to be 
formed dnb rfjs KIVTJ<TOS ru>v ala-B^^ iT^v : the case to which the dream proper 
is here restricted. 

* (Kivrjo-fv not consuetudinal aorist , but referring to the time of Kivqcriiv. 
Still it may be rendered as in the text. 

4 eco? uv <TTTJ sc. ra <f)(p6fji(va. While their movement lasts it is to this 
cause it is due. The emphasis lies on TOVTOV rbi> rporrov. The move 
ment lasts until the last thing (portion of air) has come into the place of 
the first movement eW rr/y ti )* ^ ee next note l )ut one - 


This we must likewise assume to happen in the case of 
qualitative change 1 ; for that part which [for example] has been 
heated by something hot, heats [in turn] the part next to it, 
and this propagates the affection continuously onwards until 
the process has come round to its point of origination. - This 

5 must also happen in the organ wherein the exercise of sense- 
perception takes place, since sense-perception, as realized in 
actual perceiving, is a mode of qualitative change. This 
explains why the affection continues in the sensory organs, 
both in their deeper and in their more superficial parts, not 
merely while they are actually engaged in perceiving, but even 
after they have ceased to do so. That they do this, indeed, is 
obvious in cases where we continue for some time engaged 
in a particular form of perception, for then, when we shift 
the scene of our perceptive activity, the previous affection 
remains ; for instance, when we have turned our gaze from 
sunlight :i into darkness. For the result of this is that one 

10 sees nothing, owing to the motion excited by the light 
still subsisting in our eyes. Also, when we have looked 
steadily for a long while at one colour, e. g. at white or green, 
that to which we next transfer our gaze appears to be of 

1 Not merely, as with projectiles, in change of place. 

2 (a>s rijs ap\>]s. The process of uXXot ooo-is in a material body is like that 
of ut>Ti7r(piaTa(ns (see note 457 * 2), which ends when the last thing moved 
takes the place vacated by the first. This place is 17 p\rj: i.e. 
the place o6fv 17 KIVTIVIS tip \trat. Something is here supposed to occur 
in the process of heating analogous to what occurs in the case of the 
projectile. The heat having been applied (and then withdrawn this is 
the meaning), something (corresponding to the displaced part of the air) 
is displaced by it in TO TrX^oW, which becomes hot, while that which 
was displaced again retires, and so on (KOT avraXXayrjv TO>I> TOTTGH , as 
Simplic. would say) until the process ends where it began. The air in 
successive parts retires before the stone; what retires before TO deploy? 
TO \lsvxpov or T) \lrvxpoTr)s, which for Aristotle was a positive. The con 
clusion of the process in the case of the stone is a state of rest the 
stopping of the stone. What is it in the case of Mppavais (a word 
which Bonitz omits in his Index, though it occurs 1067 12 q.i>.} i? The 
answer is 17 Gcpparrjs TOV o\i.v. With this the Kiinjais (involved in the 
ciAXouiMriff) ceases : for eanv ov% /} OfppoTtis KIVTJUIV, aXX y Otpfjuwis (io6/ b 
I2. We cannot look for an exact parallel to all this in the case of aivB^cns, 
which at most is only dAXoi oxm ns : yet something analogous to iivn- 
TrepioTucm seems to occur in the Kivfjaeis that, as it were, circulate between 
the external points of sense (eye, ear, &c.) and the Kvptov, between which 
poles the Kivijaeis and the inhibiting forces (their negatives) move. 

3 If we had been gazing at the sun itself we should not * see nothing , 
but continue to see the sun, as stated below 459 b 13. 


the same colour. Again if, after having looked at the sun 
or some other brilliant object, we close the eyes, then, if 
we watch carefully, it appears in a right line with the direction 15 
of vision (whatever this may be), at first in its own colour ; then 
it changes to crimson, next to purple, until it becomes black 
and disappears. And also when persons turn away from 
looking at objects in motion, e.g. rivers, and especially those 
which flow very rapidly, they find that the visual stimula 
tions l still present themselves, for the things really at rest are 20 
then seen moving : persons become very deaf after hearing 
loud noises, and after smelling very strong odours their power 
of smelling is impaired ; and similarly in other cases. These 
phenomena manifestly take place in the way above described. 2 
That the sensory organs are acutely sensitive to even a 
slight qualitative difference [in their objects] is shown by 
what happens in the case of mirrors ; a subject to which, 25 
even taking it independently, one might devote close" con 
sideration and inquiry. At the same time it becomes plain 
from them that as the eye [in seeing] is affected [by the 
object seen], so also it produces a certain effect upon it. 
Speculorum enim admodum nitidorum, si forte mulieres 
menstruae inspexerint, superficies sanguinea quasi nebula ?,o 
offimditur ; et novo quidem spcculo hand facile cst eius- 
modi maculam detergerc, veteri autem facilius. Quod fit 

1 Kcii . . . iiT(iftti\\oi>(Tti>. Cf. 460* 28-32 (it Kiirtj(T(is <il drro TO>V . . . 

yivupevai . . . fativovrm. From this we learn that at here agrees with 
Kneads, and that Qaivoirtu (which occurs in the clauses just before and 
after) is to be supplied in the sense of In (frmvovToi. p.(T<iftu\\ov<rtv here 
cannot be as Mich, takes it= undergo uXXouoo-i? , persistency of impression 
after transfer of gaze being the point of the sentence, not /ucruftoX*} 
on the part of the /m^o-ft? (as with the colour images just before changing 
to their complementaries, negatives, c.). We have had it in this sense 
of transfer just above 13, where pcra/SaXco/zep serves as aor. subj. of 
fura(j)fpttv b 8. The full construction then would be : *m f dno TO>I> KIVOV- 
p.ti>(t)v de \yivoucvai Ktvijirtis (rt (fruivovTui } ptTa&d\\ovo iv (TI^I/ o^nv UTTO 
TW Kii>ovp.(va>i>) ou^ KrX. Of course fl copulat, /cm intendit . It is a 
matter of indifference for sense or grammar whether after oiov we supply 
at, or /ifra/SaXXouo-i. There is no need to suspect the <u as a piece of 
dittography after ct in h 18. In 46o b 28 the conclusion of the whole 
argument is set forth. 

2 i.e. by the persistence of the qualitative change implied in all per 

It is simplest to take n(fi\ ol </$ I T< with <TKt\l/un<> <a , and understand 
of course T;)V dith mnv (or something equivalent) in the usual way with 


propterea quia visus, ut diximus, non modo patitur quippiam, 
acre agente, sed etiam facit et agit, id quod debent omnia 
quae sunt splendida. Visus enim ipse illorum est quae 
splendida sunt et colorem habent. Oculi igitur, ut con- 
sentaneum est, eadem qua quaelibet alia pars corporis ratione 
5 sc habent; suapte enim natura sunt venosi, 1 unde fit ut, dum 
menstrua perturbatione quadam sanguinis et inflammatione 
profluunt, oculi mulierum, quamvis nos quidem mares, dum 
intuemur, res fugiat (eadem 2 enim seminis quae menstruorum 
natura), mutationem subeant : illis autem motus vicinus aer 
eum quoque, qui supra speculum continuus diffunditur, aera 

10 ncscio qualem reddit, nempe talem qualiscumque iam antea 
est ipse redditus ; hie porro superficiem speculi pariter afficit. 
Ut enim vestimenta, [sic specula] quo sunt puriora, eo citius 
sordescunt. Ouaecunque enim pura sunt, si maculam acce- 
perint, aperte ostendunt, et purissimum quidque exhibet vel 
minimas turbationes. Aes vero speculare imprimis, propter 
levitatem quidem tactum qualemcunque sentit (aeris autem 

istactum oportet pro fricationc quadam et quasi expressione 
vel ablutione haberi) ; propterea autem quod purum est, 
manifeste in eo apparet tactus quantuluscumque. Quod vero 
tarde e novis speculis maculae discedunt, id fit quia speculum 
eiusmodi Icve et purum est ; namque per talia in altum et 

20 omnifariam insinuatur infectus ; in altum quidem propterea 
quod pura sunt, omnifariam autem propter levitatem. Contra 
in veteribus speculis macula idcirco non residet, quod neque 
perinde in ea penetrat, et summa tantummodo attingit. 

From this therefore it is plain that stimulatory motion is 
set up even by slight differences, and that sense- perception 
is quick to respond to it ; and further that the organ which 

. 5 perceives colour is not only affected by its object, but also 

1 <\e/3o>Seis UVTCS as if (tydaX/iot not o/n/zara had preceded. 

2 The object of the parenthetic words is to explain not the eWo-rt, but 
the fact that, although cVeort, it escapes our notice. This is due to the 
fact that the dXXoiWtr required for perception depends on the presence 
of opposites (cp. de An., where the doctrine TTCIO-^CI TO avopotov [VTTO roD 
(ivojjioiov] nnt>i>6us OJJLOIOV evTiv is laid down as fundamental). Owing 
to the identity of <J>inns here the requisite nro/ioiorf/s does not exist : 
hence 17 V rols o^aa-i T&V y. ijfilv (i8rj\os. This seems plain enough ; but 
the words in the translation have been so collocated as to exhibit it in 
the clearest lis^ht. 


reacts upon it. Further evidence to the same point is 
afforded by what takes place in wines, and in the manu 
facture of unguents. For both oil, when prepared, and 
wine become rapidly infected by the odours of the things near 
them ; they not only acquire the odours of the things thrown 30 
into or mixed with them, but also those of the things which 
are placed, or which grow, near the vessels containing them. 

In order to answer our original question, let us now, 
therefore, assume one proposition, which is clear from what 460 b 
precedes, viz. that even when the external object of perception 
has departed, the impressions it has made persist, and are 
themselves objects of perception ; and [let us assume], 
besides, that we are easily deceived respecting the operations 
of sense-perception when we are excited by emotions. 1 and 
different persons according to their different emotions ; for 
example, the coward when excited by fear, the amorous 5 
person by amorous desire ; so that, with but little resemblance 
to go upon, the former thinks he sees his foes approaching, 
the latter, that he sees the object of his desire ; and the more 
deeply one is under the influence of the emotion, the less 
similarity is required to give rise to these illusory impressions. 
Thus too, both in fits of anger, and also in all states of appe 
tite, all men become easily deceived, and more so the more their 
emotions are excited. This is the reason too why persons 
in the delirium of fever sometimes think they see animals 
on their chamber walls, an illusion arising from the faint 
resemblance to animals of the markings thereon when put 
together in patterns ; and this sometimes corresponds with 
the emotional states of the sufferers, in such a way that, if the 
latter be not very ill, they know well enough that it is an 
illusion ; but if the illness is more severe they actually move 15 
according to the appearances.- The cause of these occur- 

1 fv TT(iB((Tii OVT(S . . . o SfiXdr, KiX. The fieiXos = the person whose 
disposition or character inclines him to take fright ; the faftos = the 
fright he gets into at any particular time. So with 6 epuriKos and his 
(pus. TriWrj here not = passions , as this word is generally understood in 
psychological English. See Hoffding (E.T.), p. 282, where passion and 
4 emotion are defined. For ndOos x 1 ?, see N.E. iic>5 b 21-26. 

2 -npos nvr<i : they regulate their movements with a view to them or 
with relation to them : i. e. move away from them or towards them, as if 
they were real. 


rences is that the faculty in virtue of which the controlling 
sense judges is not identical with that in virtue of which 
presentations come before the mind. A proof of this is. 
that the sun presents itself as only a foot in diameter, 
though often something 1 else gainsays the presentation. 

20 Again, when the fingers are crossed, the one object [placed 
between them] is felt [by the touch] as two ; but yet we 
deny that it is two ; for sight is more authoritative than 
touch. Yet, if touch stood alone, we should actually have 
pronounced the one object to be two. The ground of such 
false judgments is that any appearances whatever present 
themselves, not only when its object stimulates a sense, 
but also when the sense by itself alone 2 is stimulated, 

25 provided only it be stimulated in the same manner :{ as it 
is by the object. For example, to persons sailing past 
the land seems to move, 4 when it is really the eye that is 
being moved by something else [the moving ship]. 


From this it is manifest that the stimulatory movements based 

upon sensory impressions, whether the latter are derived from 

external objects or from causes within the body, present them- 

?,o selves " not only when persons are awake, but also then, when 

1 As some senses are more authoritative than others, so TO Kpivov is 
more authoritative than TO <aira0TiKoV, and even than any particular 
sense. The judgment, which recognizes the superior authority of sight 
and makes us say ($an*v) that the objects are not two, but one. is what 
Aristotle here wishes to emphasize. 

2 Without an object. 

:: The importance of this in explaining the illusion of dreams appears 
fully in 461 b 28-9. 

4 jurcurdru, Kii/oi /zcfqi- are here both used of local movement, while 
KIVOVVTO?, KivovfjLttnjf, just above were used of sense-stimulation. 

Biehl s text has been translated. eywyo^oTw : we have a gen. absol. 
(not a dative after (fraivovrai) because when awake people do not 
notice them, although they are there. The claiv supplied by Mich. 
in first clause is not necessary. h 29 TO>I> nltrf^ur^v : the impressions 
of sense as distinct from the exercises of sense aI<r0T)<Ttts. TO>> Ovpadn 
. . . -ruv ( K ror (T. impressions derived from objects in space around 
us X impressions of our bodily states, e. g. twinges of pain, &c. aiaBrf 
fiuToof agrees with TU>V K(\\ TMV. V.wnopxovaatv in liiehl s text must be wrong, 
for we cannot believe in his anacoluthia. The case is not like (ftXefttodas 
, 460* 5 ; for there, at least, there is a new sentence, and the subject 

is grammatically different. I ut we cannot part with alffBripaTuv here: 
nio6i)(Tt<i)v would contradict 459 :l 27 Cm fXdova-atv and 460^ 2 (<iirfA#<Wa>j ); 


this affection which is called sleep has come upon them, with 
even greater 1 impressiveness. For by day, while the senses 
and the intellect are working together,- they (i. e. such move 
ments) are extruded from consciousness or obscured, just as 461 a 
a smaller is beside a larger fire, or as small beside great pains 
or pleasures, though, as soon as the latter have ceased, even 
those which are trifling emerge into notice. But by night 
[i. e. in sleep] owing to the inaction of the particular senses, 
and their powerlessness to realize themselves, which arises 
from the reflux of the hot from the exterior parts to the 5 
interior, they [i. e. the above movements ] are borne in :{ to 
the head quarters of sense-perception, and there display them 
selves as the disturbance (of waking life) subsides. We must 
suppose that, like the little eddies which are being ever formed 
in rivers, so the sensory movements are each a continuous 
process, often remaining like what they were when first 10 
started, but often, too, broken into other forms by collisions 
with obstacles. This [last mentioned point], moreover, gives 
the reason why no dreams occur in sleep immediately after 
meals, or to sleepers who are extremely young, e.g.. to infants. 
The internal movement in such cases is excessive, owing to 
the heat generated from the food. Hence, just as in a liquid, 
if one vehemently disturbs it, sometimes no reflected image 15 
appears, while at other times one appears, indeed, but utterly 

the doctrine being that dreams are based UTTU TVV at 0-0/; /iui-a>i> or TTO rmv 
Kii///afcoj/r&>i/ mV#r?/i<JTa> , the aiffQrpfis of which have departed. Cf. 461* 19 
and 462* 30. We should, therefore (in spite of MSS.), read evvTrap\ov(riv t 
with Bywater,/. / . xxviii. 243, 46i b 30. Besides it is emphatically not the 
but their Ktvi jvds or aiVdq/zara that abide within : cf. 459* 01 
\fi (v TOIS al(T0i]TT)piois (vcpyovawv TtO)V ala&i}(T(u)V, XAa xai 
Keeping Biehl s text, however, (/>aiVotrat 46o b 32 goes with 
the preceding clause also, even without zeugma : for the Kivrja-ets can be 
said <paii>(T0(n JyprjyopoTtov = to present themselves u>hcn people are 
awake, though they do not (jxtivovrai typrjyopoviv, i.e. appear to or get 
noticed by them. 

1 Kal p.a\\ov. The trans. even more has the advantage of requiring 
fpnivm Tat to be supplied but once, viz. in the <w pwov clause. We 
get a perfectly good construction by making *ai the copula, but then must 
supply (paivovTdL twice. Besides Ka\pa\\ov=velmagis is a stock expression. 

* 1vv(pyovcru>v should be (isfpyovcroiv of which it is an attempted correction 
in EMY; (i) it perverts Aristotle s meaning, as the r^-operation of altrB. 
and bidvota is not necessary for the extrusion of the Kivfjacis ; (2) Aristotle 
nowhere else uses (rwepydv absolutely, nor can we supply here raly 
Ktv^(T(nv ; (3) cf. 46 1 a 5, alibi) where (vtpydv is used de re eadem. 

3 Karafpepovrm, borne in (to the icvpiov m<r0.) from ra mVtfr/T^pin, in which 


distorted, so as to seem quite unlike its original ; while, when 
once the motion has ceased, the reflected images are clear 
and plain ; in the same manner during sleep the phantasms, 
or residuary movements, which are based upon the sensory 
impressions, become sometimes quite obliterated by the 

20 above described motion when too violent ; while at other 
times the sights are indeed seen, but confused and weird, and 
the dreams [which then appear] are unhealthy, like those 
of persons who are atrabilious, or feverish, or intoxicated with 
wine. For all such affections, being spirituous, cause much 
commotion and disturbance. In sanguineous animals, in pro- 

25 portion as the blood becomes calm, and as its purer are 
separated from its less pure elements, the fact that the 
movement, based on impressions derived from each of 
the organs of sense, is preserved in its integrity, renders the 
dreams healthy, causes a [clear] image to present itself, 
and makes the dreamer think, owing to the effects borne in 
from the organ of sight, that he actually sees, and owing to 
those which come from the organ of hearing, that he really 

30 hears ; and so on with those also which proceed from the 
other sensory organs. For it is owing to the fact that 
the movement which reaches the primary organ of sense 
comes from them, that one even when awake believes him- 
461 b self to see, or hear, or otherwise perceive ; just as it is from 
a belief that the organ of sight is being stimulated, 1 though 
in reality not so stimulated, that we sometimes erroneously 
declare ourselves to see, or that, from the fact that touch 
announces two movements, we think that the one object is 
two. For, as a rule, the governing sense affirms the report 
of each particular sense, unless another particular sense, more 
r authoritative, makes a contradictory report. In every case 
an appearance presents itself, but what appears does not in 
every case seem real, unless when the deciding faculty is 
inhibited, or does not move with its proper motion. More 
over, as we said that different men are subject to illusions, 
each according to the different emotion present in him, so it is 
that the sleeper, owing to sleep, and to the movements then 
going on in his sensory organs, as well as to the other facts 

1 By objective visual impressions. 


of the sensory process, [is liable to illusion], so that the 10 
dream presentation, though but little like it, appears as some 
actual given thing. For when one is asleep, in proportion as 
most of the blood sinks inwards to its fountain [the heart], 
the internal [sensory] movements, some potential, others 
actual l accompany it inwards. They are so related [in 
general] that, if anything move the blood, some one 
sensory movement will emerge from it, while if this perishes 
another will take its place; while to one another also they ,- 
are related in the same way as the artificial frogs in water 
which severally rise [in fixed succession] to the surface in the 
order in which the salt [which keeps them down] becomes 
dissolved. The residuary movements are like these : they arc 
within the soul potentially, but actualize themselves only 
when the impediment to their doing so has been relaxed ; 
and according as 2 they are thus set free, they begin to move 
in the blood which remains in the sensory organs, and which 
is now but scanty/ while they possess verisimilitude after the 
manner of cloud-shapes, which in their rapid metamorphoses --o 
one compares now to human beings and a moment afterwards 
to centaurs. Each of them is however, as has been said, the 
remnant of a sensory impression taken when sense was 
actualizing itself; and when this, the true impression, 4 has 
departed, its remnant is still immanent, and it is correct to say 
of it, that though not actually Koriskos, it is like Koriskos. 
For 5 when the person was actually perceiving, his controlling 25 

1 The actual are those in consciousness at the time when one is falling 
asleep : the potential, those which had before that subsided into latency. 
Cf. 46i a I. 

2 Xi/d^ei/nt : i. e. successively and severally : pres. part, has its force 
(all through these tracts such points are most carefully observed). 

3 The most favourable condition, disturbance being at its minimum. 

carefully distinguished from TO alaBrma the impression merely, when 
the aia-fftjrov is gone. 

5 Mich, explains & as = yap. rightly ; for the 6/^oioVf;f of the uTroXet/x^a 
is derived from that of the d\i)d(s aio-QrjfjLa. But he is wrong when he 
makes ore y<r6m>tTO = ore tv TCO VTTVU) ov KaTfi ^ero VTTO roO m/xnrof. The 
past tense might have warned him against doing so. Both this and 
the av p} navT(\a>s refer to what happens in waking and normal 
consciousness. The detection of a dream as such in sleep is men 
tioned below (462* 3) as an exceptional occurrence, and not part of the 
dream proper ; to introduce it here would only confuse, not illustrate 


and judging sensory faculty did not call it ^ Koriskos. but, 
prompted by this [impression], called the genuine person 
yonder Koriskos. Accordingly, this sensory impulse, which, 
when actually perceiving, it [the controlling faculty] so 
describes (unless completely inhibited by the blood), it 
now [in dreams], when quasi-perceiving. - receives from 
the movements persisting in the sense-organs, and mistakes 
it an impulse that is merely like the true 15 [objective] 
impression for the true impression itself, while the effect 
o of sleep is so great that it causes this mistake to pass 
unnoticed. Accordingly, just as if a finger be inserted 
beneath the eyeball without being observed, one object will 

as Aristotle means to do. Mich, is right, however, in making ov ft?) 
. . . alfJMTOs bt]\a>TiK<>v TOV oTf 8t ^ar0avfTo. Biehl, in stating that Mich, 
read ///} after a>o-7r*/>, b 27, makes a mistake. Wendland s (Mich., p. 73. 
12) note is u><nvt p cum Arist. EMSUY (axr^ep pt} L). See next 
note but one. 

5 The impression synchronous with actual perception. 

2 tofTTrqj aurQavdpfvov. In the translation the text of Biehl has not been 
followed. The retention (with Biehl, after L) of py after o)(rntp b 27, or its 
omission (with Mich, and EMYSU), makes a great difference. It ought to 
be omitted : wo-nep nt(T0avofj.tvov is in sense opposed to KU\ wafiavofjuvov b 26, 
and to oVf ^V^<n 6ro b 24, as the dreaming to the waking consciousness. \Yhen 
one was actually percipient, the Kvpiov did not confound even TO mo-fl^ci TO 
u\r)6fs with Ko/x o-jcoff n uXrjQivns, nor does it when actually percipient ever 
do so unless under some pathological condition ; yet (see 460 b 25) in the 
quasi-percipient state of sleep, when not perceiving TO aio-tfrj/ia TO aAqde r 
at all, but only its MAtc/ipi. it is moved with this same movement (TOUTO 
Kivdrai, cf. 463 b 1 8 1, and made to treat this (the wroAetyi/ua) not only as 
if it were TO d\t]6fs mo-d^/ia, but as if it were a real thing. After ma6rjTrj- 
piois b 29 there should be only a comma. The waking aio-^/na is only olov 
Ko/n o-KOf, not actually K. The remanent ruo-$/7/na too is, but only in a 
secondary degree, oioi/ K. Vet so great is the power of sleep that the 
critical faculty, which in waking moments (unless inhibited completely) 
docs not mistake even the genuine mvd^a for its object, when asleep 
confounds distinctions, and mistaking the remanent ala-drj^a for the object, 
is unaware of this mistake. 

b 29, nuToi with op.oi<iv. ii\r,6(s here and above is to be kept distinct 
from (iXrjdivns, as truthful from genuine , according to the usual 
meanings of these words. 6 a\r)0ivb$ K. = the genuine Koriskos : TO 
(iXtjOts aiffBrj^a = the impression which tells truth, i. e. the immediate 
impression of K. yonder, as distinct from the vTroXci^a, which speaks of 
him as if there when he is not there. Hence it is that d\rj0(s and avro) 
should not be referred to the external thing. Two degrees of error 
(whence the strong expression TOOCIVTTJ 17 Swapis) are usual in dreams : 

(.7) the ai(r6r)p.a TO vnoXourov is Confounded with TO madrj^n TO dXrjOes ; 
(b) no distinction is drawn between TO nurtfq/ja TO d\i]6(s and TO irpayfu 
TO d\T)6iv(>v. This fine analysis is (or may have been) founded on Plato, 
Republic, 4?6 C TO 6vflpd>TTiv upd ov To^e eo"Tt r, ttiv T( (V vnva> TIS tiiv T 
tos TO o^ioiov TCO ^i^ op.otov <iAA ai To fjyrjTnt civai (*> totKfV | 


not only present two visual images, but will create an opinion 
of its being two objects ; while if it [the finger] be observed, the 
presentation will be the same, but the same opinion will not 
be formed of it ; exactly so it is in states of sleep : if the 
sleeper perceives that he is asleep, and is conscious of 
the sleeping state during which the perception comes before 
his mind, it presents itself still, but something within him ? 
speaks to this effect : the image of Koriskos presents itself, 
but the real Koriskos is not present ; for often, when one is 
asleep, there is something in consciousness which declares 
that what then presents itself is but a dream. If, however, 
he is not aware of being asleep, there is nothing which will 
contradict the testimony of the bare presentation. 

That what we here urge is true, i.e. that there are such 
presentative movements in the sensory organs, any one may 
convince himself, if he attends to and tries to remember the i 
affections we experience when sinking into slumber or when 
being awakened. He will sometimes, in the moment of 
awakening, surprise the images which present themselves to 
him in sleep, and find that they are really but movements 
lurking in the organs of sense. And indeed some very young 
persons, if it is dark, though looking with wide open eyes, 1 
see multitudes of phantom figures moving before them, so that 
they often cover up their heads in terror. 

From all this, then, the conclusion to be drawn is, that the 15 
dream is a sort of presentation, and, more particularly, one 
which occurs in sleep; since the phantoms just mentioned 
are not dreams, nor is any other a dream which presents 
itself when the sense-perceptions are in a state of freedom. 
Nor is every presentation which occurs in sleep necessarily 
a dream. For in the first place, some persons [when asleep] 
actually, in a certain way, perceive sounds, light, savour, and 20 
contact ; feebly, however, and, as it were, remotely. For 
there have been cases in which persons while asleep, but with 
the eyes partly open, saw faintly in their sleep (as they 
supposed) the light of a lamp, and afterwards, on being 
awakened, straightway recognized it as the actual light of 
a real lamp ; while, in other cases, persons who faintly heard 

1 8uift\(7roi>T(s x viroftXtnovrts, 462** 22. 

-AK PX 1 1 

462 a DE SOMNI1S 

25 the crowing of cocks or the barking of dogs identified these 
clearly with the real sounds as soon as they awoke. Some 
persons, too, return answers to questions put to them in sleep. 
For it is quite possible that, of waking or sleeping, while the 
one is present in the ordinary sense, the other also should be 
present in a certain way. But none of these occurrences 1 
should be called a dream. Nor should the true thoughts, 2 
as distinct from the mere presentations, which occur in sleep [be 
called dreams]. The dream proper is a presentation based 

30 on the movement of sense impressions, when such presentation 
occurs during sleep, taking sleep in the strict sense of the 

There are cases of persons who in their whole lives have 
462 b never had a dream, while others dream when considerably 
advanced in years, having never dreamed before. The cause 
of their not having dreams appears somewhat like that which 
operates in the case of infants, and [that which operates] 
immediately after meals. It is intelligible enough that no 
5 dream-presentation should occur to persons whose natural 
constitution is such that in them copious evaporation is 
borne upwards, which, 3 when borne back downwards, causes a 
large quantity of motion. But it is not surprising that, as age 
advances, a dream should at length appear to them. Indeed, 

10 it is inevitable that, as a change is wrought 4 in them in 
proportion to age or emotional experience, this reversal 
[from non-dreaming to dreaming] should occur also. 

1 Those due to this ambiguous condition. 

2 aXq&is cwoim : e. g. when one says to himself this is only a dream . 
Cf. supra 462* 6. 

s Reading 7) ... Kara^pofitvr) noicl with I S U and Themistius. Biehl s 
text is wrong, for it implies that the upward movement of the apadi>/it a<m 
causes sleep. Cf. supra 456 b 26-8. 

4 If we keep yivopfvijf (which suits KU& f]\tKiai ) we must give it its 
continuative or progressive sense. This progressive change keeps pace 
with their change of age, and with the succession of (or vicissitudes of) n<i0r) 
which they experience. Kara mi6os does not mean in consequence of 
something that has happened to them , or in consequence of some one 



As to the divination which takes place in sleep, and is said 
to be based on dreams, we cannot lightly either dismiss it with 
contempt or give it implicit confidence. The fact that all per 
sons, or many, suppose dreams to possess a special significance, 
tends to inspire us with belief in it [such divination], as founded i; 
on the testimony of experience ; and indeed that divination in 
dreams should, as regards some subjects, be genuine, is not 
incredible, for it has a show of reason ; from which one might 
form a like opinion also respecting all other dreams. Yet the 
fact of our seeing no probable cause to account for such 
divination tends to inspire us with distrust. For, in addition to 20 
its further unreasonableness, it is absurd to combine 1 the idea 
that the sender of such dreams should be God with the fact 
that those to whom he sends them are not the best and wisest, 
but merely commonplace persons. If, however, we abstract 
from the causality of God, none of the other causes assigned 
appears probable. For that certain persons should have fore 
sight in dreams concerning things destined to take place at the 
Pillars of Hercules, or on the banks of the Borysthenes, seems ;; 
to be something to discover the explanation of which surpasses 
the wit of man. Well then, the dreams in question must be 
regarded either as causes, or as tokens, of the events, or else as 
coincidences ; either as all, or some, of these, or as one only. 
I use the word cause in the sense in which the moon is 

1 b 20-22. Bichl s comma after iri^novra is wrong, unless another 
comma be put after dXoyi a. The clause npus 77; a\\Tj tiXoyui, which is 
parenthetic, refers to the abandonment of reason already noticed in 
pt)dcpiav atYmv (v\oyov just before. Besides the general a\oyia of referring 
dreams to u 6c6s, there is the special uronia of his sending them to poor 
creatures, not to wise men (cf. 463 b 15). The constr. is : TO r* ... tlvm 
KO.I TO ... n-fnTTfiv it is the conjunction of the two things that is peculiarly 
UTOTTOI/. Thus TC and /cm are in their usual correlation here. 

II 2 


[the cause] of an eclipse of the sun, or in which fatigue is 
30 [a cause] of fever ; token [in the sense in which] the entrance 
of a l star [into the shadow] is a token of the eclipse, or [in 
which] roughness of the tongue [is a token] of fever ; while 
by coincidence I mean, for example, the occurrence of an 
eclipse of the sun while some one is taking a walk ; for the 

463 a walking is neither a token nor a cause of the eclipse, nor 

the eclipse [a cause or token] of the walking. For this 
reason no coincidence takes place according to a universal 
or general rule. Are we then to say that some dreams 
are causes, others tokens, e. g. of events taking place in the 
bodily organism ? At all events, even scientific physicians tell 
5 us that one should pay diligent attention to dreams, and to 
hold this view is reasonable also for those who are not 
practitioners, but speculative philosophers. Eor the move 
ments which occur in the daytime [within the body] are, 
unless very great and violent, lost sight of in contrast with the 

10 waking movements, which are more impressive. In sleep the 
opposite takes place, for then even trifling movements seem 
considerable. This is plain in what often happens during sleep ; 
for example, dreamers fancy that they are affected by thunder 
and lightning, when in fact there are only faint ringings in their 
cars ; or that they are enjoying honey or other sweet savours, 
when only a tiny drop of phlegm is flowing down [the 

15 oesophagus] ; or that they are walking through fire, and 
feeling intense heat, when there is only a slight warmth 
affecting certain parts of the body. When they are awakened, 
these things appear to them in this their true character. 
But since the beginnings of all events are small, so, it is 
clear, are those also of the diseases or other affections about 

20 to occur in our bodies. In conclusion, it is manifest that these 
beginnings must be more evident in sleeping than in waking 

Nay, indeed, it is not improbable that some of the presenta 
tions which come before the mind in sleep may even be 

1 TUV (\(TT(pa = a star or any star : the star that does show out, whatever 
star it be. The article is generic. The eta-- not = * into our view but = 
into the shadow, when however, of course, it also comes into our view. 
Bonitz, Ind. t queries t*j(\6<1v here : why ? The first star we see 
betokens the coming eclipse. 

CHAPTER I 463 a 

causes of the actions cognate to each of them. For as when 
we are about to act [in waking hours], or are engaged in any 
course of action, or have already performed certain actions, 
we often find ourselves concerned with these actions, or per- 25 
forming them, in a vivid dream ; the cause whereof is that 
the dream- movement has had a way paved for it from the 
original movements set up in the daytime ; exactly so, but 
conversely, it must happen that the movements set up 
first in sleep should also prove to be starting-points of actions 
to be performed in the daytime, since the recurrence by day 
of the thought of these actions also has had its way paved for 
it in the images before the mind at night. Thus then it is 3^ 
quite conceivable that some dreams may be tokens and causes 
[of future events]. 

Most [so-called prophetic] dreams are, however, to be 
classed as mere coincidences, especially all such as are ex- 463 b 
travagant, and those in the fulfilment of which the dreamers 
have no initiative, such as in the case of a sea-fight, or of things 
taking place far away. As regards these it is natural that the 
fact should stand as it does whenever a person, on mentioning 
something, finds the very thing mentioned come to pass. Why, 5 
indeed, should this not happen also in sleep? The proba 
bility is, rather, that many such things should happen. As, 
then, one s mentioning a particular person is neither token 
nor cause of this person s presenting himself, so, in the parallel 
instance, the dream is, to him who has seen it, neither token 
nor cause of its [so-called] fulfilment, but a mere coincidence. 
Hence the fact that many dreams have no fulfilment , for 
coincidences do not occur according to any universal or 10 
general law. 


On the whole, forasmuch as certain of the lower animals also 
dream, it may be concluded that dreams are not sent by God, 
nor are they designed for this purpose [to reveal the future]. 
They have a divine aspect, 1 however, for Nature [their cause] 

fifVToi, / yap^ixris daipovtu, aXX ov 6da. Bonitz (Illd. 464* 28) 
followed by L. and S. (sub voc. daipovios) explains 0iVts> here as 17 TWV 
vvis. Zeller, Arist. i. 421 (E. T.) takes the right view. 


! 5 is divinely planned, though not itself divine. A special proof 
[of their not being sent by God] is this : the power of fore 
seeing the future and of having vivid dreams is found in 
persons of inferior type, which implies that God does not 
send their dreams ; but merely that all those whose physical 
temperament is, as it were, garrulous and excitable, see: 
sights of all descriptions ; for, inasmuch as they experience 
many movements of every kind, they just chance to have 
visions resembling objective facts, their luck in these matters 

30 being merely like that of persons who play at even and odd. 1 
For the principle which is expressed in the gambler s maxim : 
If you make many throws your luck must change, holds 
good in their case also. 

That many dreams have no fulfilment is not strange, for 
it is so too with many bodily symptoms and weather-signs, 

25 c. g., those of rain or wind. For if another movement occurs 
more influential than that from which, while [the event to which 
it pointed was] still future, the given token was derived, the 
event [to which such token pointed] does not take place. So. 
of the things which ought to be accomplished by human agency, 
many, though well-planned, are by the operation of other prin 
ciples more powerful [than man s agency] brought to nought. 
For, speaking generally, that which was about to happen is not 
in every case what now is happening : nor is that which shall 
hereafter be identical with that which is now going to be. 

30 Still, however, we must hold that the beginnings from 
which, as we said,- no consummation follows, are real begin 
nings, and these constitute natural tokens of certain events, 
even though the events do not come to pass. 

As for [prophetic] dreams which involve not such beginnings 
[sc. of future events] as we have here described, but such as 
are extravagant in times, or places, or magnitudes : or those 

If (/mm were to be thus limited we should have had <wru>v. Nature in 
general is bai^ovid as the province and theatre of God s final causation, 
and dreams (which are fyvviKii} partake of the character of Nature their 
cause. The general difference between 6is and Sm^i/, $elo? and dot/iowpiy 
(that the 5m)ia>j/ is the offspring of the #*<>$, the Saipnviov the handiwork of 
the dftov) is here preserved. 

1 Reading dprt<i(ovT(s, Bekker s conj. 

OVK Tf\t<r6r} : such is the force of the aor. For meaning of TIVI IS cf. 
notes 440* 28. 


involving beginnings which arc not extravagant in any of 
these respects, 1 while yet the persons who see the dream 
hold not in their own hands the beginnings [of the event 
to which it points] : unless the foresight which such dreams 
give is the result of pure coincidence, the following 
would be a better explanation of it than that pro 
posed by Democritus, who alleges images and emana- 5 
tions as its cause. As, when something has caused 
motion in water or air, this [the portion moved] moves 
another [portion of water or air], and, though the cause has 
ceased to operate, such motion propagates itself to a certain 
point, though there the prime movent is not present ; just so 
it may well be that a movement and a consequent sense-per 
ception should reach sleeping souls from the objects from which 10 
Democritus represents images and * emanations as coming ; 
that such movements, in whatever way they arrive, should be 
more perceptible at night [than by day], because when pro 
ceeding thus in the daytime they are more liable to dissolu 
tion (since at night the air is less disturbed, there being then 
less wind); and that they shall be perceived within the body 15 
owing to sleep, since persons are more sensitive even to slight 
sensory movements when asleep than when awake. It is 
these movements then that cause presentations , as a result 
of which sleepers foresee the future even relatively to such 
events as those referred 2 to above. These considerations 
also explain why this experience befalls commonplace persons 20 
and not the most intelligent. For it would have regularly oc 
curred both in the daytime and to the wise had it been God 
who sent it ; but, as we have explained the matter, it is quite 
natural that commonplace persons should be those who have 
foresight [in dreams]. For the mind of such persons is not 
given to thinking, but, as it were, derelict, or totally vacant, 
and. when once set moving, is borne passively on in the direc 
tion taken by that which moves it. With regard to the fact 
that some persons who are liable to derangement have this j-j 

2. ) TOVTOV p.ti> p.ijtv . SC. vTTfpnpas TUS ap\ay e 
Mr;S<?f is acc. of respect after vnepopias understood from the previous 
clause. Perhaps /zr/5eW would have been plainer : but the construction 
is easy enough. Biehl by his proposed correction avrols . . . rols Iftovm 
would seem to construe as if /zqfieV depended on e^oi/rwi/ directly. 
i. e. those referred to 464* I 4. 


foresight, its explanation is that their normal mental move 
ments do not impede [the alien movements], but arc beaten 
off by the latter. Therefore it is that they have an especially 
keen perception of the alien movements. 

That certain persons in particular should have vivid 
dreams, e. g. that familiar friends should thus have foresight 
in a special degree respecting one another, is due to the fact 
that such friends are most solicitous on one another s behalf. 

30 For as acquaintances in particular recognize and perceive one 
another a long way off, so also they do as regards the sensory 
movements respecting one another ; for sensory movements 
which refer to persons familiarly known are themselves more 
familiar. Atrabilious persons, owing to their impetuosity, 1 are, 
when they, as it were, shoot from a distance, expert at hitting ; 
464 b while, owing to their mutability, the series of movements 
deploys quickly before their minds. For even as the insane 
recite, or con over in thought, the poems of Philaegides,- e. g. 
the Aphrodite, whose parts succeed in order of similitude, just 
so do they [the atrabilious ] go on and on stringing sensory 
movements together. Moreover, owing to their aforesaid 
5 impetuosity, one movement within them is not liable to be 
knocked out of its course by some other movement. 

The most skilful interpreter of dreams is he who has the 
faculty of observing resemblances. Any one may interpret 
dreams which are vivid and plain. But, speaking of resem 
blances , I mean that dream presentations are analogous to 
the forms reflected in water, as indeed we have already stated. 

10 In the latter case, if the motion in the water be great, the 
reflexion has no resemblance to its original, nor do the forms 
resemble the real objects. Skilful, indeed, would he be in 
interpreting such reflexions who could rapidly discern, and at 
a glance comprehend, the scattered and distorted fragments 

1 Which do not suffer them to wait until the object of their speculation 
is near them. 

2 Probably should be Qi\mvidos, a name found in Lucian, rseudologista^ 
24, and Athenaeus 335 B-E. But what were the poems referred to ? 
Did they go on like The House that Jack built ? Ath. and Luc. 
do not help to explain the point here, and Mich, and Pseudo-Them. add 
nothing to what our passage yields. Michael only contrasts the desultory 
manner of Euripides with the consistency of Philaegides in keeping to 
a theme. 


of such forms, so as to perceive that one of them represents 
a man, or a horse, or anything whatever. Accordingly, in the 15 
other case also, in a similar way, some such thing as this 
[blurred image] is all that a dream amounts T to ; for the 
internal movement effaces the clearness of the dream. 

The questions, therefore, which we proposed as to the nature 
of sleep and the dream, and the cause to which each of them 
is due, and also as to divination as a result of dreams, in every 
form of it, have now been discussed. 

1 1( 15. The troubled dream has this effect , SiVarm roCro. The KOMI 
prevents us from taking TOVTO with TO evvirvmv = * the dream we speak of 
has a certain effect. To explain n it is necessary, after Kiehl s conjecture, 
to read roioOro. There is no analogy for TOVTO TL : TOOC TI is a totally different 
kind of expression. But roiotro n would be not only correct, but quite to 
the point here. Not rt, but TTCOS, should qualify o/zo:W. 



THE reasons for some animals being long-lived and others 
,-o short-lived, and. in a word, the causes of the length and 
brevity of life call for investigation. 

The necessary beginning to our inquiry is a statement of 
the difficulties about these points. For it is not clear whether 
in animals and plants universally it is a single or diverse 
cause that makes some to be long-lived, others short-lived. 
5 Plants too have in some cases a long life, while in others it 
lasts but for a year. 

Further, in a natural structure are longevity and a sound 
constitution coincident, or is shortness of life independent of 
unhealthiness ? Perhaps in the case of certain maladies a 
diseased state of the body and shortness of life are inter- 
;,o changeable, while in the case of others ill-health is perfectly 
compatible with Jong life. 

Of sleep and waking we have already treated ; about life 
and death we shall speak later on, and likewise about health 
and disease, in so far as it belongs to the science of nature 
465 a to do so. But at present we have to investigate the causes of 
some creatures being long-lived, others short-lived. We 
find this distinction affecting not only entire genera opposed 
as wholes to one another, but applying also to contrasted sets l 
of individuals within the same species.- As an instance of 

1 See next sentence, sub Jin. 

~ Aristotle does not mention the opposition of species to species, but 
passes at once from the maximum of difference (generic) to the minimum 
< individual). In the next sentence, however, we have a case of specific 
diversity (man and horse). It is strange for him to say that the difference 
of man and horse in longevity is a difference Kara -yeVos, and that between 
man and man (who must be individuals (< iv ddos) *ar dtios. Unless 
we translate in the fashion I have adopted we must believe that there is 
a confusion in the first sentence between yevos and 6toy, and that when 
in the second he does distinguish between them Aristotle contradicts the 
rest of his teaching. 

CHAPTER I 465 a 

the difference applying to the genus I give man and horse 5 
(for mankind has a longer life than the horse), while within 
the species there is the difference between man and man ; for 
of men also some are long-lived, others short-lived, differing 
from each other in respect of the different regions in which 
they dwell. Races inhabiting warm countries have longer 
life, those living in a cold climate live a shorter time. Like- 10 
wise there are similar differences among individuals occupying 
the same locality. 


In order to find premisses for our argument, we must 
answer the question, What is that which, in natural objects, 
makes them easily destroyed, or the reverse ? Since fire 
and water, and whatsoever is akin thereto, do not possess J5 
identical powers they are reciprocal causes of generation and 
decay. Hence it is natural to infer that everything else 
arising from them and composed of them should share in the 
same nature, in all cases where things are not, like a house, 
a composite unity formed by the synthesis of many things. 

In other matters a different account must be given ; for 
in many things their mode of dissolution is something 
peculiar to themselves, e. g. in knowledge and health and 20 
disease. These pass away even though the medium in 
which they are found is not destroyed but continues to 
exist ; for example, take the termination of ignorance, which 
is recollection or learning, while knowledge passes away into 
forget fulness, or error. But accidentally the disintegration of 
a natural object is accompanied by the destruction of the 
non-physical reality : for. when the animal dies, the health 25 
or knowledge resident in it passes away too. Hence from 
these considerations we may draw a conclusion about the 
soul too ; for. if the inherence of soul in body is not a matter 
of nature but like that of knowledge in the soul, there would 
be another mode of dissolution pertaining to it besides that 
which occurs when the body is destroyed. But since evidently 30 
it does not admit of this dual dissolution, the soul must stand 
in a different case in respect of its union with the body. 



Perhaps one might reasonably raise the question whether 
there is any place where what is corruptible becomes incor 
ruptible, as fire does in the upper regions where it meets 
with no opposite. Opposites destroy each other, and hence 
5 accidentally, by their destruction, whatsoever is attributed to 
them is destroyed. But no opposite in a real substance is 
accidentally destroyed, because real substance is not predi 
cated of any subject. Hence a thing which has no opposite, 
or which is situated where it has no opposite, cannot be 
destroyed. For what will that be which can destroy it, if 
destruction comes only through contraries, but no contrary to 

10 it exists cither absolutely or in the particular place where it 
is ? But perhaps this is in one sense true, in another sense 
not true, for it is impossible that anything containing matter 
should not have in any sense an opposite. Heat and 
straightness can be present in every part of a thing, but it is 
impossible that the thing should be nothing but hot or white 
or straight ; for, if that were so, attributes would have an 

15 independent existence. Hence if, in all cases, whenever the 
active and the passive exist together, the one acts and the 
other is acted on, it is impossible that no change should occur. 
Further, this is so if a waste product is an opposite, and waste 
must always be produced ; for opposition is always the source 
of change, and refuse is what remains of the previous opposite. 
But, after expelling everything of a nature actually opposed, 
would an object in this case also be imperishable ? No, it 

jo would be destroyed by the environment. 

If then that is so, what we have said sufficiently accounts 
for the change ; but. if not, we must assume that something 
of actually opposite character is in the changing object, and 
refuse is produced. 

Hence accidentally a lesser flame is consumed by a greater 

25 one, for the nutriment 1 , to wit the smoke, which the former 
takes a long period to expend, is used up by the big flame 

1 Read i}i/ rpofyrjv with Bywater, Journal of Philol. xxviii. p. 243, 
instead of Biehl s 17 rpo^i? rjv. This obviates the necessity of treating 
TOV KUTTVOV as a gloss. 


Hence [too] all things are at all times in a state of 
transition and are coming into being and passing away. 
The environment acts on them either favourably or antago 
nistically, and, owing to this, things that change their 
situation become more or less enduring than their nature 
warrants, but never are they eternal when they contain con 
trary qualities; for their matter is an immediate source of 3 
contrariety, so that if it involves locality they show change of 
situation, if quantity, increase and diminution, while if it 
involves qualitative affection we find alteration of character. 


We find that a superior immunity from decay attaches 466 a 
neither to the largest animals (the horse has shorter life 
than man) nor to those that are small (for most insects 
live but for a year). Nor are plants as a whole less 
liable to perish than animals (many plants are annuals), 
nor have sanguineous animals the pre-eminence (for the bee 
is longer-lived than certain sanguineous animals). Neither 5 
is it the bloodless animals that live longest (for molluscs 
live only a year, though bloodless), nor terrestrial organisms 
(there are both plants and terrestrial animals of which a 
single year is the period), nor the occupants of the sea 
(for there we find the crustaceans and the molluscs, which 
are short-lived). 

Speaking generally, the longest-lived things occur among 
the plants, e.g. the date-palm. Next in order we find 10 
them among the sanguineous animals rather than among the 
bloodless, and among those with feet rather than among the 
denizens of the water. Hence, taking these two characters 
together, the longest-lived animals fall among sanguineous 
animals which have feet, e. g. man and elephant. As a 
matter of fact also it is a general rule that the larger 
live longer than the smaller, for the other long-lived animals i.; 
too happen to be of a large size, as are also those I have 


The following considerations may enable us to understand 
the reasons for all these facts. We must remember that an 


20 animal is by nature humid and warm, and to live is to be of 
such a constitution, while old age is dry and cold, and so is 
a corpse. This is plain to observation. But the material con 
stituting the bodies of all things l consists of the following 
the hot and the cold, the dry and the moist. Hence when they 
age they must become dry, and therefore the fluid in them 
requires to be not easily dried up. Thus we explain why 
fat things are not liable to decay. The reason is that they 
contain air ; now air relatively to the other elements is fire, 

25 and fire never becomes corrupted. 

Again the humid element in animals must not be small in 
quantity, for a small quantity is easily dried up. This is why 
both plants and animals that are large are, as a general rule, 
longer-lived than the rest, as was said before ; it is to be 
expected that the larger should contain more moisture. But 
it is not merely this that makes them longer lived ; for the 

30 cause is twofold, to wit. the quality as well as the quantity 
of the fluid. Hence the moisture must be not only great in 
amount but also warm, in order to be neither easily congealed 
nor easily dried up. 

It is for this reason also that man lives longer than some 

animals which are larger ; for animals live longer though there 

466 b is a deficiency in the amount of their moisture, if the ratio of 

its qualitative superiority exceeds that of its quantitative 


In some creatures the warm element is their fatty substance, 
which prevents at once desiccation and congelation ; but in 
others it assumes a different flavour. 2 Eurther, that which is 
; designed to be not easily destroyed should not yield waste 
products. Anything of such a nature causes death either 
by disease or naturally, for the potency of the waste product 
works adversely and destroys now the entire constitution, 
now a particular member. 

This is why salacious animals and those abounding in seed 

1 I thus translate ro ts ovin (Biehl). Bywater suggests TOIOVTOIS instead 
of ouo-t (Journal of Philol. xxviii. p. 244). If this conjecture is adopted 
the translation will be In such cases the material of which the body is 
composed consists, &c. 

2 TO Xnrupvv is one of the recognized flavours ;" c/."V& Sens.] chdp. iv. 
442" 17 sqq. 

CHAPTER V 466 b 

age quickly ; the seed is a residue, and further, by being lost, 
it produces dryness. Hence the mule lives longer than either 
the horse or the ass from which it sprang, and females live I0 
longer than males if the males are salacious. Accordingly 
cock-sparrows have a shorter life than the females. Again 
males subject to great toil are short-lived and age more 
quickly owing to the labour ; toil produces dryness and 
old age is dry. But by natural constitution and as a general 
rule males live longer than females, and the reason is that 15 
the male is an animal with more warmth than the female. 

The same kind of animals are longer-lived in warm than in 
cold climates for the same reason, on account of which they 
are of larger size. The size of animals of cold constitution 
illustrates this particularly well, and hence snakes and lizards ->o 
and scaly reptiles are of great size in warm localities, as also 
are testacea in the Red Sea : the warm humidity there is the 
cause equally of their augmented size and of their life. But 
in cold countries the humidity in animals is more of a watery 
nature, and hence is readily congealed. Consequently it 
happens that animals with little or no blood are in northerly ^5 
regions either entirely absent (both the land animals with feet 
and the water creatures whose home is the sea) or, when they 
do occur, they are smaller and have shorter life ; for the frost 
prevents growth. 

Both plants and animals perish if not fed, for in that case 
they consume themselves; just as a large flame consumes & 
and burns up a small one by using up its nutriment, so the 
natural warmth which is the primary cause of digestion 
consumes the material in which it is located. 

Water animals have a shorter life than terrestrial creatures, 
not strictly because they are humid, but because they are 4^7 a 
watery, and watery moisture is easily destroyed, since it is 
cold and readily congealed. For the same reason bloodless 
animals perish readily unless protected by great size, for there 
is neither fatness nor sweetness about them. In animals fat 
is sweet, and hence bees are longer-lived than other animals 5 
of larger size. 



It is amongst the plants that we find the longest life- 
more than among the animals, for, in the first place, they are 
less watery and hence less easily frozen. Further they have 
an oiliness and a viscosity which makes them retain their 
moisture in a form not easily dried up, even though they are 
dry and earthy. 

10 But we must discover the reason why trees are of an endur 
ing constitution, for it is peculiar to them and is not found 
in any animals except the insects. 

Plants continually renew themselves and hence last for 
a long time. New shoots continually come and the others 
grow old, and with the roots the same thing happens. But 
both processes do not occur together. Rather it happens 

*5 that at one time the trunk and the branches alone die and 
new ones grow up beside them, and it is only when this has 
taken place that the fresh roots spring from the surviving 
part. Thus it continues, one part dying and the other grow 
ing, and hence also it lives a long time. 

There is a similarity, as has been already said, between 
plants and insects, for they live, though divided, and two 

20 or more may be derived from a single one. Insects, how 
ever, though managing to live, are not able to do so long, 
for they do not possess organs ; nor can the principle resident 
in each of the separated parts create organs. In the case of 
a plant, however, it can do so ; every part of a plant contains 
potentially both root and stem. Hence it is from this source 
that issues that continued growth when one part is renewed 

- 5 and the other grows old ; it is practically a case of longevity. 1 
The taking of slips furnishes a similar instance, for we might 
say that, in a way, when we take a slip the same thing 
happens ; the shoot cut off is part of the plant. Thus in 
taking slips this perpetuation of life occurs though their 
connexion with the plant is severed, but in the former case it 
is the continuity that is operative. The reason is that the 

30 life principle potentially belonging to them is present in 
every part. 

1 raj MSS. (except. S. roj et edd. TOV conicio. 


Identical phenomena are found both in plants and in 
animals. For in animals the males are, in general, the longer- 
lived. They have their upper parts larger than the lower 
(the male is more of the dwarf 1 type of build than the 
female), and it is in the upper part that warmth resides, in 
the lower cold. In plants also those with great heads are 
longer-lived, and such are those that are not annual but of the 467 b 
tree-type, for the roots arc the head and upper part of 
a plant, and among the annuals growth occurs in the direc 
tion of their lower parts and the fruit. 

These matters however will be specially investigated in the 
work On Plants. - But this is our account of the reasons 5 
for the duration of life and for short life in animals. It 
remains for us to discuss youth and age, and life and death. 
To come to a definite understanding about these matters 
would complete our course of study on animals. 

1 i.e. with trunk and head disproportionately lar<;e. 

2 Not extant. 



10 WE must now treat of youth and old age and life and 
death. We must probably also at the same time state the 
causes of respiration as well, since in some cases living and 
the reverse depend on this. 

We have elsewhere given a precise account of the soul, and 
while it is clear that its essential reality cannot be corporeal, 

15 yet manifestly it must exist in some bodily part which must 
be one of those possessing control over the members. Let 
us for the present set aside the other divisions or faculties of 
the soul (whichever of the two be the correct name). But 
as to being what is called an animal and a living thing, we 
find that in all beings endowed with both characteristics 

20 (viz. being an animal and being alive) there must be a single 
identical part in virtue of which they live and are called 
animals ; for an animal qua animal cannot avoid being alive. 
But a thing need not, though alive, be animal, for plants live 
without having sensation, and it is by sensation that we 

25 distinguish animal from what is not animal. 

This organ, then, must be numerically one and the same 
and yet possess multiple and disparate aspects, for being 
animal and living are not identical. Since then the organs 
of special sensation have one common organ in which the 

30 senses when functioning must meet, and this must be situated 
midway between what is called before and behind (we call 
before the direction from which sensation comes, * behind 
the opposite), further, since in all living things the body is 
divided into upper and lower (they all have upper and lower 
parts, so that this is true of plants as well), clearly the nutri- 
468 a tive principle must be situated midway between these regions. 
That part where food enters we call upper, considering it by 

CHAPTER I 468 a 

itself and not relatively to the surrounding universe, while 
downward is that part by which the primary excrement 1 is 

Plants are the reverse of animals in this respect. To man 5 
in particular among the animals, on account of his erect 
stature, belongs the characteristic of having his upper parts 
pointing upwards in the sense in which that applies to the 
universe, while in the others these are in an intermediate 
position. But in plants, owing to their being stationary and 
drawing their sustenance from the ground, the upper part 
must always be down ; for there is a correspondence between 
the roots in a plant and what is called the mouth in animals, 10 
by means of which they 2 take in their food, whether the 
source of supply be the earth or each other s bodies. 


All perfectly formed animals are to be divided into three 
parts, one that by which food is taken in, one that by which 
excrement is discharged, and the third the region inter- i 5 
mediate between them. In the largest animals this latter is 
called the chest and in the others something corresponding; 
in some also it is more distinctly marked off than in others. 
All those also that are capable of progression have additional 
members subservient to this purpose, by means of which they 
bear the whole trunk, to wit legs and feet and whatever parts 
are possessed of the same powers. Now it is evident both 20 
by observation and by inference that the source of the nutri 
tive soul is in the midst of the three parts. For many 
animals, when either part the head or the receptacle of the 

1 By this 1 imagine that TO rr/s KinXins rrfpiTTui^a (de Part. Animal, in. 
chap. viii. 67 i a 7) is meant, or more generally TO T^S rpo^rjs (n. chap. vii. 
653" 13, &c.). Besides what we should call excrement, many bodily 
secretions, e. g. yovi] and yuXa, are called nfpiTT^^ara by Aristotle. 

2 I take TO. p.iv and r 3e (468* u, 12) to refer to different classes of 
animals. Herbivorous animals could be said to derive their food e x TTJ? 
yf}s ; the other class consists of the carnivora. On the other hand, if 
Aristotle means to contrast two classes of plants, the second set those 
which get their nutriment & f nvrau/ will comprise grafts and parasitic 
plants, which only derive food indirectly from the soil . Cf. Ogle, 
Aristotle on Youth and Old Age, &c., p. 108. 


J 5 food is cut off, retain life in that member to which the mid 
dle remains attached. This can be seen to occur in many 
insects, e.g. wasps and bees, and many animals also besides 
insects can, though divided, continue to live by means of the 
part connected with nutrition. 

While this member is indeed in actuality single, yet poten 
tially it is multiple, for these animals have a constitution 

30 similar to that of plants ; plants when cut into sections 
continue to live, and a number of trees can be derived 
from one single source. A separate account l will be given 
of the reason why some plants cannot live when divided, 
468 b while others can be propagated by the taking of slips. In 
this respect, however, plants and insects are alike. 

It is true 2 that the nutritive soul, in beings possessing it. 
while actually single must be potentially plural. And so 
it is too with the principle of sensation, for evidently the 
5 divided segments of these animals have sensation. They are 
unable, however, to preserve their constitution, as plants can, 
not possessing the organs on which the continuance of life 
depends, for some lack the means for seizing, others for 
receiving their food ; or again they may be destitute of other 
organs as well. 

Divisible animals are like a number of animals grown 

10 together, but animals of superior construction behave differ 
ently because their constitution is a unity of the highest 
possible kind. Hence some of the organs on division display 
slight sensitiveness because they retain some psychical suscep 
tibility ; the animals continue to move after the vitals have 

15 been abstracted: tortoises, for example, do so even after the 
heart has been removed. 


The same phenomenon is evident both in plants and in 
animals, and in plants we note it both in their propagation 
by seed and in grafts and cuttings. Genesis from seeds 
always starts from the middle. All seeds are bivalvular, and 

1 In the extant works of Aristotle no such account is to be met with. 
Some suppose that it was included in the lost treatise on plants. 

2 Susemihl and Biehl read 8fi. 


the place of junction 1 is situated at the point of attachment 1 20 
(to the plant), an intermediate part belonging to both halves. 
It is from this part that both root and stem of growing things 
emerge ; the starting-point is in a central position between 
them. In the case of grafts and cuttings this is particularly 
true of the buds ; for the bud is in a way the starting-point 
of the branch, but at the same time it is in a central position. 25 
Hence it is either this that is cut off. or into this that the new 
shoot is inserted, when we wish either a new branch or a 
new root to spring from it ; which proves that the point of 
origin in growth is intermediate between stem and root. 

Likewise in sanguineous animals the heart is the first organ 
developed ; this is evident from what has been observed in 
those cases where observation of their growth is possible. 
Hence in bloodless animals also what corresponds to the 30 
heart must develop first. We have already asserted in our 
treatise on The l\irts of Animals- that it is from the heart 
that the veins issue, and that in sanguineous animals the blood 469 a 
is the final nutriment from which the members are formed. 
Hence it is clear that there is one function in nutrition which 
the mouth has the faculty of performing, and a different one 
appertaining to the stomach. Hut it is the heart that has 
supreme control, exercising an additional and completing 
function. Hence in sanguineous animals the source both of 5 
the sensitive and of the nutritive soul must be in the heart, 
for the functions relative to nutrition exercised by the other 
parts are ancillary to the activity of the heart. It is the part 
of the dominating organ to achieve the final result, as of the 
physician s efforts to be directed towards health, and not to 
be occupied with subordinate offices. 

Certainly, however, all sanguineous animals have the to 
supreme organ of the sense-faculties in the heart, for it is 
here that we must look for the common sensorium belonging 

1 I have followed Bekker s reading / (Ti nnf<f>vK(i> t \frat . KOI TO ntvov 
KT\. Biehl conjectures / avij.nt<t>vK.(v (ipx*) Tf Kal T0 pta-ov the point of 

junction is the starting-point and intermediate between the two halves. 
But if o-vpirtyvKfv has the same force as irpoa-jr^vKf in de den. Animal. 
752* 19, 23 (q. ? .) it refers to the attachment of the seed to the plant. 
Again, the sense which e^trai here bears is closely akin to that which we 
meet with in the participle f^o/ifvoy. 
Cf. dt? Part. Animal, iii. 665* 15. 


to all the sense-organs. These in two cases, taste and touch, 
can be clearly seen to extend to the heart, and hence the 

Bothers also must lead to it, for in it the other organs may 
possibly initiate changes, whereas \vith the upper region of 
the body taste and touch have no connexion. Apart from 
these considerations, if the life is always located in this part, 
evidently the principle of sensation must be situated there 
too, for it is qua animal that an animal is said to be a living 
thing, and it is called animal because endowed with sensation. 

20 Elsewhere in other works l we have stated the reasons why 
some of the sense-organs are, as is evident, connected with the 
heart, while others are situated in the head. (It is this fact 
that causes some people to think that it is in virtue of the 
brain that the function of perception belongs to animals.) 


Thus if, on the one hand, we look to the observed facts, 
what we have said makes it clear that the source of the 
sensitive soul, together with that connected with growth and 

2; nutrition, is situated in this organ and in the central one of the 
three divisions of the body. But it follows by deduction also ; 
for we see that in every case, when several results are open to 
her, Nature always brings to pass the best. Now if both 

30 principles are located in the midst of the substance, the two 
parts of the body, viz. that which elaborates and that which 
receives the nutriment in its final form will best perform their 
appropriate function ; for the soul will then be close to each, 
and the central situation which it will, as such, occupy is the 
position of a dominating power. 

469 b Further, that which employs an instrument and the instru 
ment it employs must be distinct (and must be spatially 
diverse too, if possible, as in capacity), just as the flute and 
that which plays it the hand are diverse. Thus if animal is 
defined by the possession of sensitive soul, this soul must in 
5 the sanguineous animals be in the heart, and, in the bloodless 
ones, in the corresponding part of their body. But in animals 
all the members and the whole body possess some connate 

1 de Piirt. AninniL ii. 656 5. 


warmth of constitution, and hence when alive they are ob 
served to be warm, but when dead and deprived of life they 
are the opposite. Indeed, the source of this warmth must be 10 
in the heart in sanguineous animals, and in the case of blood 
less animals in the corresponding organ, for, though all parts 
of the body by means of their natural heat elaborate and 
concoct the nutriment, the governing organ takes the chief 
share in this process. Hence, though the other members 
become cold, life remains ; but when the warmth here is 
quenched, death always ensues, because the source of heat 
in all the other members depends on this, and the soul is, 15 
as it were, set aglow with fire in this part, which in san 
guineous animals is the heart and in the bloodless order the 
analogous member. Hence, of necessity, life must be coin 
cident with the maintenance of heat, and what we call death 
is its destruction. 20 


However, it is to be noticed that there are two ways in 
which fire ceases to exist : it may go out either by exhaus 
tion or by extinction. That which is self-caused we call 
exhaustion, that due to its opposites extinction. [The 
former is that due to old age, the latter to violence. 1 ] But 
either of these ways in which fire ceases to be may be 
brought about by the same cause, for, when there is a 
deficiency of nutriment and the warmth can obtain no 25 
maintenance, the fire fails ; and the reason is that the oppo 
site, checking digestion, prevents the fire from being fed. 
But in other cases the result is exhaustion, when the heat 
accumulates excessively owing to lack of respiration and of 
refrigeration. For in this case what happens is that the 
heat, accumulating in great quantity, quickly uses up its 
nutriment and consumes it all before more is sent up by 30 
evaporation. Hence not only is a smaller fire readily put 
out by a larger one, but of itself- the candle flame is consumed 

1 Biehl thinks that an erroneous interpretation has suggested this clause. 

2 The going out of the fire is, in every case of ndpavatx, in one respect 
caused by the burning body itself, i.e. by its burning, and hence con 
suming its fuel. It \spt-r accidens (Kara o-vp.j3((3r)Kos : 465 23 above) that 
it is put out owing to the consumption of its fuel by a larger fire. 


when inserted in a large blaze, just as is the case with any 
other combustible. The reason is that the nutriment in the 
flame is seized by the larger one before fresh fuel can be 
added, for fire is ever coming into being and rushing just 
like a river, but so speedily as to elude observation. 

5 Clearly therefore, if the bodily heat must be conserved 
(as is necessary if life is to continue), there must be some 
way of cooling the heat resident in the source of warmth. 
Take as an illustration what occurs when coals are confined 
in a brazier. If they are kept covered up continuously by the 

10 so-called choker , they are quickly extinguished, but, if the 
lid is in rapid alternation lifted up and put on again they 
remain glowing for a long time. Banking up a fire also 
keeps it in, for the ashes, being porous, do not prevent the 
passage of air, and again they enable it to resist extinction 
by the surrounding air by means of the supply of heat which 

15 it possesses. However, we have stated in TJic Problems 1 
the reasons why these operations, namely banking up and 
covering up a fire, have the opposite effects (in the one case 
the fire goes out, in the other it continues alive for a consider 
able time). 


20 Everything living- has soul, and it 2 , as we have said, 
cannot exist without the presence of heat in the constitution. 
In plants the natural heat is sufficiently well kept alive by 
the aid which their nutriment and the surrounding air supply. 
For the food has a cooling effect [as it enters, just as it has 
in man] 3 when first it is taken in, whereas abstinence from 

.25 food produces heat and thirst. The air, if it be motionless, 
becomes hot, but by the entry of food a motion is set up 
which lasts until digestion is completed and so cools it. If 
the surrounding air is excessively cold owing to the time 
of year, there being severe frost, plants shrivel, or if, in 
the extreme heats of summer the moisture drawn from the 

30 ground cannot produce its cooling effect, the heat comes to 

1 No such passage is found in the extant Problems. 

- 1. 19. Read a>r and nfri;. 

8 This clause seems to be an interpolation. 

CHAPTER VI 47<> a 

an end by exhaustion. Trees suffering at such seasons are 
said to be blighted or star-stricken. Hence the practice of 
laying beneath the roots stones of certain species or water 
in pots, for the purpose of cooling the roots of the plants. 

Some animals pass their life in the water, others in the air, 47 b 
and therefore these media furnish the source and means of 
refrigeration, water in the one case, air in the other. We 
must proceed and it will require further application on our 
part to give an account of the way and manner in which 5 
this refrigeration occurs. 


(Chapter I of that part which deals specially with Respiration ) 

A few of the previous physical philosophers have spoken 
of respiration. The reason, however, why it exists in animals 
they have either not declared or, when they have, their 
statements are not correct and show a comparative lack of 
acquaintance with the facts. Moreover they assert that all 
animals respire which is untrue. Hence these points must ro 
first claim our attention, in order that we may not be thought 
to make unsubstantiated charges against authors no longer 

First then, it is evident that all animals with lungs breathe, 
but in some cases breathing animals have a bloodless and 
spongy lung, and then there is less need for respiration. 
These animals can remain under water for a time, which 15 
relatively to their bodily strength, is considerable. All 
oviparous animals, e.g. the frog-tribe, have a spongy lung. 
Also hemydes and tortoises can remain for a long time im 
mersed in water ; for their lung, containing little blood, has 20 
not much heat. Hence, when once it is inflated, it itself, by 
means of its motion, produces a cooling effect and enables the 
animal to remain immersed for a long time. Suffocation, 
however, always ensues if the animal is forced to hold its 
breath for too long a time, for none of this class take in 
water in the way fishes do. On the other hand, animals which 
have the Jung qharged with blood have greater need of- 5 


respiration on account of the amount of their heat, while 
none at all of the others which do not possess lungs, 


Democritus of Abdera and certain others who have treated 
of respiration, while saying nothing definite about the lungless 

30 animals, nevertheless seem to speak as if all breathed. But 
Anaxagoras and Diogenes both maintain that all breathe, 
and state the manner in which fishes and oysters respire. 
Anaxagoras says that when fishes discharge water through 
471 a their gills, air is formed in the mouth, for there can be no 
vacuum, and that it is by drawing in this that they respire. 
Diogenes statement is that, when they discharge water 
through their gills, they suck the air out of the water 
surrounding the mouth by means of the vacuum formed in 
the mouth, for he believes there is air in the water. 
5 But these theories are untenable. Firstly, they state only 
what is the common element in both operations and so leave 
out the half of the matter. For what goes by the name of 
respiration consists, on the one hand, of inhalation, and, on the 
other, of the exhalation of breath ; but, about the latter they 
say nothing, nor do they describe how such animals emit 

10 their breath. Indeed, explanation is for them impossible for, 
when the creatures respire, they must discharge their breath 
by the same passage as that by which they draw it in, and 
this must happen in alternation. Hence, as a result, they 
must take the water into their mouth at the same time as 
they breathe out. But the air and the water must meet and 
obstruct each other. Further, when they discharge the water 

15 they must emit their breath by the mouth or the gills, and 
the result will be that they will breathe in and breathe out at 
the same time, for it is at that moment that respiration is said 
to occur. But it is impossible that they should do both at 
the same time. Hence, if respiring creatures must both 
exhale and inhale the air, and if none of these animals can 
breathe out, evidently none can respire at all. 

4?i a 

Further, the assertion that they draw in air out of the 20 
mouth or out of the water by means of the mouth is an 
impossibility, for, not having a lung, they have no windpipe ; 
rather the stomach is closely juxtaposed to the mouth, so that 
they must do the sucking with the stomach. But in that 
case the other animals would do so also, which is not the 
truth ; and the water-animals also would be seen to do it 
when out of the water, whereas quite evidently they do not. 2 5 
Further, in all animals that respire and draw breath there is 
to be observed a certain motion in the part of the body 
which draws in the air, but in the fishes this does not occur. 
Fishes do not appear to move any of the parts in the region 
of the stomach, except the gills alone, and these move both 
when they are in the water and when they are thrown on to 3 
dry land and gasp. Moreover, always when respiring animals 471 b 
are killed by being suffocated in water, bubbles are formed of 
the air which is forcibly discharged, as happens, e. g. when 
one forces a tortoise or a frog or any other animal of a similar 
class to stay beneath water. But with fishes this result never 
occurs, in whatsoever way we try to obtain it, since they do 
not contain air drawn from an external source. Again, the 5 
manner of respiration said to exist in them might occur in 
the case of men also when they are under water. For if 
fishes draw in air out of the surrounding water by means of 
their mouth why should not men too and other animals do 
so also ; they should also, in the same way as fishes, draw in 
air out of the mouth. 1 If in the former case it were possible, 10 
so also should it be in the latter. But, since in the one it is 
not so, neither does it occur in the other. Furthermore, 
why do fishes, if they respire, die in the air and gasp (as can 
be seen) as in suffocation ? It is not want of food - that pro 
duces this effect upon them, and the reason given by Diogenes 15 
is foolish, for he says that in air they take in too much air 
and hence die, but in the water they take in a moderate 
amount. But that should be a possible occurrence with land 

1 Anaxagoras s theory. 

2 If the air is regarded as nutriment. 


animals also ; as facts are, however, no land animal seems to 
be suffocated by excessive respiration. Again, if all animals 

20 breathe, insects must do so also. But many of them seem 
to live though divided not merely into two, but into several 
parts, e. g. the class called Scolopendra. But how can they, 
when thus divided, breathe, and what is the organ they 
employ ? The main reason why these writers have not given 
a good account of these facts is that they have no acquaint- 

25 ance with the internal organs, and that they did not accept 
the doctrine that there is a final cause for whatever Nature 
docs. If they had asked for what purpose respiration exists 
in animals, and had considered this with reference to the 
organs, e. g. the gills and the lungs, they would have dis 
covered the reason more speedily. 


30 Democritus, however, does teach that in the breathing 
animals there is a certain result produced by respiration ; 
he asserts that it prevents the soul from being extruded from 
472 a the body. Nevertheless, he by no means asserts that it is 
for this purpose that Nature so contrives it, for he, like the 
other physical philosophers, altogether fails to attain to any 
such explanation. His statement is that the soul and the hot 
element are identical, being the primary forms among the 
5 spherical particles. Hence, when these are being crushed 
together by the surrounding atmosphere thrusting them out, 
respiration, according to his account, comes in to succour 
them. For in the air there are many of those particles which 
he calls mind and soul. Hence, when we breathe and the 
air enters, these enter along with it, and by their action cancel 
the pressure, thus preventing the expulsion of the soul which 
resides in the animal. 

10 This explains why life and death are bound up with the 
taking in and letting out of the breath ; for death occurs 
when the compression by the surrounding air gains the upper 
hand, and, the animal being unable to respire, the air from 
outside can no longer enter and counteract the compression. 

CHAPTER X (IV) 472 a 

Death is the departure of those forms owing to the expulsive 15 
pressure exerted by the surrounding air. Death, however, 
occurs not by haphazard but, when natural, owing to old age. 
and, when unnatural, to violence. 

But the reason for this and why all must die Democritus 
has by no means made clear. And yet, since evidently death 
occurs at one time of life and not at another, he should have 
said whether the cause is external or internal. Neither docs 20 
he assign the cause of the beginning of respiration, nor say 
whether it is internal or external. Indeed, it is not the case 
that the external mind superintends the reinforcement ; rather 
the origin of breathing and of the respiratory motion must be 
within : it is not due to pressure from around. It is absurd 
also that what surrounds should compress and at the same 
time by entering dilate. This then is practically his theory, . 5 
and ho\v he puts it. 

But if we must consider that our previous account is true, 
and that respiration does not occur in every animal, we must 
deem that this explains death not universally, but only in 
respiring animals. Yet neither is it a good account of these 
even, as may clearly be seen from the facts and phenomena 30 
of which we all have experience. For in hot weather we 
grow warmer, and, having more need of respiration, we always 
breathe faster. But, when the air around is cold and contracts 
and solidifies the body, retardation of the breathing results. 
Yet this was just the time when the external air should enter 35 
and annul the expulsive movement, whereas it is the opposite 472 b 
that occurs. For when the breath is not let out and the heat 
accumulates too much then we need to respire, and to respire 
we must draw in the breath. When hot. people breathe rapidly, 
because they must do so in order to cool themselves, just 5 
when the theory of Democritus would make them add fire 
to fire. 


The theory found in the Timaeus, of the passing round of 
the breath by pushing, by no means determines how, in the 
case of the animals other than land -animals, their heat is pre 
served, and whether it is due to the same or a different cause. 


For if respiration occurs only in land-animals we should be 

10 told what is the reason of that. Likewise, if it is found in 
others also, but in a different form, this form of respiration, 
if they all can breathe, must also be described. 

Further, the method of explaining involves a fiction. It is 
said that when the hot air issues from the mouth it pushes 
the surrounding air, which being carried on enters the very 

15 place whence the internal warmth issued, through the inter 
stices of the porous flesh ; and this reciprocal replacement is 
due to the fact that a vacuum cannot exist. But when it has 
become hot the air passes out again by the same route, and 
pushes back inwards through the mouth the air that had 
been discharged in a warm condition. It is said that it is 
this action which goes on continuously when the breath is 
taken in and let out. 

- o But according to this way of thinking it will follow that 
we breathe out before we breathe in. But the opposite is 
the case, as evidence shows, for though these two functions 
go on in alternation, yet the last act when life comes to 
a close is the letting out of the breath, and hence its 
admission must have been the beginning of the process. 

Once more, those who give this kind of explanation by no 
means state the final cause of the presence in animals of this 

25 function (to wit the admission and emission of the breath), 
but treat it as though it were a contingent accompaniment 
of life. Yet it evidently has control over life and death, for 
it results synchronously that when respiring animals are 
unable to breathe they perish. Again, it is absurd that the 

30 passage of the hot air out through the mouth and back again 
should be quite perceptible, while we were not able to detect 
the thoracic influx and the return outwards once more of the 
heated breath. It is also nonsense that respiration should 
consist in the entrance of heat, for the evidence is to the 
contrary effect ; what is breathed out is hot, and what is 

35 breathed in is cold. When it is hot we pant in breathing, 
473 a for, because what enters does not adequately perform its 
cooling function, we have as a consequence to draw the breath 

473 a 

It is certain, however, that we must not entertain the notion 
that it is for purposes of nutrition that respiration is designed, 
and believe that the internal fire is fed by the breath ; 
respiration, as it were, adding fuel to the fire, while the feeding 5 
of the flame results in the outward passage of the breath. 
To combat this doctrine I shall repeat what I said in opposition 
to the previous theories. This, or something analogous to it, 
should occur in the other animals also (on this theory), for 
all possess vital heat. Further, how are we to describe this 10 
fictitious process of the generation of heat from the breath ? 
Observation shows rather that it is a product of the food. 
A consequence also of this theory is that the nutriment would 
enter and the refuse be discharged by the same channel, but 
this docs not appear to occur in the other instances. 


Empedocles also gives an account of respiration without. 15 
however, making clear what its purpose is, or whether or not 
it is universal in animals. Also when dealing with respiration 
by means of the nostrils he imagines he is dealing with what 
is the primary kind of respiration. Even the breath which 
passes through the nostrils passes through the windpipe out 
of the chest as well, and without the latter the nostrils cannot 20 
act. Again, when animals are bereft of respiration through the 
nostrils, no detrimental result ensues, but. when prevented from 
breathing through the windpipe, they die. Nature employs 
respiration through the nostrils as a secondary function in 
certain animals in order to enable them to smell. But the - 5 
reason why it exists in some only is that though almost 
all animals are endowed with the sense of smell, the sense- 
organ is not the same in all. 

A more precise account has been given about this else 
where. 1 Empedocles, however, explains the passage inwards 473 b 
and outwards of the breath, by the theory that there are 

1 Cf. de An. iii. 421* 10, de Sens. ch. v. 443* 4, 444 7-15, Hist. An. 
iv. 534 b 16, de Part. Animal, ii. 659 b 15. 


certain blood-vessels, which, while containing blood, arc not 
filled by it, but have passages leading to the outer air, the 
calibre of which is fine in contrast to the size of the solid 
5 particles, but large relatively to those in the air. Hence, 
since it is the nature of the blood to move upwards and 
downwards, when it moves down the air rushes in and 
inspiration occurs ; when the blood rises, the air is forced 
out and the outward motion of the breath results. He 
compares this process to what occurs in a clepsydra. 

Thus all things outwards breathe and in ; their flesh has 

10 Bloodless, that stretch towards the body s outmost edge, 
Which, at their mouths, full many frequent channels pierce. 
Cleaving the extreme nostrils through ; thus, while the gore 
Lies hid, for air is cut a thoroughfare most plain. 
And thence, whenever shrinks away the tender blood. 

15 Enters the blustering wind with swelling billow wild. 

But when the blood leaps up, backward it breathes. As 


With water-clock of polished bronze * a maiden sporting, 
Sets on her comely hand the narrow of the tube 
And dips it in the frail-formed water s silvery sheen ; 

jo Not then the flood the vessel enters, but the air, 
Pressing within on the dense orifices, checks it, 
Until she frees the crowded stream. But then indeed 
Upon the air s escape runs in the water meet. 
So also when within the vessel s deeps the water 

25 Remains, the opening by the hand of flesh being closed, 
The outer air that entrance craves restrains the flood 
At the gates of the sounding narrow, upon the surface 

474 a Until the maid withdraws her hand. But then in contrariwise 

Once more the air comes in and water meet flows out. 
Thus too the subtle blood, surging throughout the limbs, 
Whene er it shrinks away into the far recesses 
Admits a stream of air rushing with swelling wave, 
5 But, when it backward leaps, in like bulk air flows out. 

This then is what he says of respiration. But, as we said. 
all animals that evidently respire do so by means of the 
windpipe, when they breathe either through the mouth or 

1 The reading is difficult. Perhaps we should read K\t^v^pijt Trm^tat 
nA*o(o, with Diels, Vorsokratiker^ 2nd ed., p. 200. 


through the nostrils. Hence, if it is of this kind of respira 
tion that he is talking, we must ask how it tallies with the 10 
explanation given. But the facts seem to be quite opposed. 
The chest is raised in the manner of a forge-bellows when 
the breath is drawn in it is quite reasonable that it should 
be heat which raises up and that the blood should occupy the 
hot region but it collapses and sinks down, like the bellows 
once more, when the breath is let out. The difference is that 15 
in a bellows it is not by the same channel that the air is 
taken in and let out, but in breathing it is. 

But, if Empedocles is accounting only for respiration 
through the nostrils, he is much in error, for that does not 
involve the nostrils alone, but passes by the channel beside 
the uvula where the extremity of the roof of the mouth is, 20 
some of the air going this way through the apertures of 
the nostrils and some through the mouth, both when it enters 
and when it passes out. Such then is the nature and magni 
tude of the difficulties besetting the theories of other writers 
concerning respiration. 


We have already stated that life and the presence of soul 2 5 
involve a certain heat. Not even the digesting process to 
which is due the nutrition of animals occurs apart from soul 
and warmth, for it is to fire that in all cases elaboration is 
due. It is for this reason, precisely, that the primary 
nutritive soul also must be located in that part of the 3 
body and in that division of this region which is the 
immediate vehicle of this principle. The region in question 474 
is intermediate between that where food enters and that 
where excrement is discharged. In bloodless animals it 
has no name, but in the sanguineous class this organ is 
called the heart. The blood constitutes the nutriment 
from which the organs of the animal are directly formed. 
Likewise the blood-vessels must have the same originating 5 
source, since the one exists for the other s behoof as a 
vessel or receptacle for it. In sanguineous animals the 
heart is the starting-point of the veins ; they do not traverse 


it, but are found to stretch out from it, as dissections l enable 
us to see. 

10 Now the other psychical faculties cannot exist apart from 
the power of nutrition (the reason has already been stated in 
the treatise on the soul), 2 and this depends on the natural 
fire, by the union with which Nature has set it aglow. But 
fire, as we have already stated, is destroyed in two ways, 
either by extinction or by exhaustion. It suffers extinction 

15 from its opposites. Hence it can be extinguished by the 
surrounding cold both when in mass and (though more 
speedily) when scattered. Now this way of perishing is 
due to violence equally in living and in lifeless objects, 
for the division of an animal by instruments and consequent 
congelation by excess of cold cause death. But exhaustion 

20 is due to excess of heat ; for, if there is too much heat close 
at hand and the thing burning does not have a fresh supply 
of fuel added to it, it goes out by exhaustion, not by the 
action of cold. Hence, if it is going to continue it must be 
cooled, for cold is a preventive against this form of 


25 Some animals occupy the water, others live on land, and, 
that being so, in the case of those which are very small and 
bloodless the refrigeration due to the surrounding water or 
air is sufficient to prevent destruction from this cause. Having 

30 little heat, they require little cold to combat it. Hence 
too such animals are almost all short-lived, for, being small, 
they have less scope for deflection towards either extreme. 
475 a But some insects are longer-lived (though bloodless, like all 
the others), and these have a deep indentation beneath the 
waist, in order to secure cooling through the membrane, 
which there is thinner. They are warmer animals and hence 
require more refrigeration, and such are bees (some of which 
5 live as long as seven years) and all that make a humming 
noise, like wasps, cockchafers, and crickets. They make 
a sound as if of panting by means of air, for, in the middle 

1 According to Bonitz, hid. p. lO4 a 6, the reference here and at 478* 35 
is to a lost treatise of Aristotle s on Anatomy. 

2 De An. i. 4ii b 18, ii. 4i3 b I. 

CHAPTER XV (IX) 475 a 

section itself, the air which exists internally and is involved 
in their construction, causing a rising and falling movement, 
produces friction against the membrane. The way in which 
they move this region is like the motion due to the lungs 1 
in animals that breathe the outer air, or to the gills in fishes. 
What occurs is comparable to the suffocation of a respiring 
animal by holding its mouth, for then the lung causes a 
heaving motion of this kind. In the case of these animals 
this internal motion is not sufficient for refrigeration, but 
in insects it is. It is by friction against the membrane 5 
that they produce the humming sound, as we said, in the 
way that children do by blowing through the holes of a reed 
covered by a fine membrane. It is thus that the singing 
crickets too produce their song ; they possess greater warmth 
and are indented at the waist, but the songless variety have 
no fissure there. 

Animals also which are sanguineous and possess a lung, 20 
though that contains little blood and is spongy, can in some 
cases, owing to the latter fact, live a long time without 
breathing; for the lung, containing little blood or fluid, can 
rise a long way : its own motion can for a long time produce 
sufficient refrigeration. But at last it ceases to suffice, and 25 
the animal dies of suffocation if it does not respire as we 
have already said. For of exhaustion that kind which is 
destruction due to lack of refrigeration is called suffocation, 
and whatsoever is thus destroyed is said to be suffocated. 

We have already stated that among animals insects do not 
respire, and the fact is open to observation in the case of even 30 
small creatures like flies and bees, for they can swim about in 
a fluid for a long time if it is not too hot or too cold. Yet 475 b 
animals with little strength tend to breathe more frequently. 
These, however, die of what is called suffocation when the 
stomach becomes filled and the heat in the central segment 
is destroyed. This explains also why they revive after being 
among ashes for a ti